Patent Publication Number: US-2022217102-A1

Title: Bulk message deletion

Description:
CLAIM OF PRIORITY 
     This application is a continuation of U.S. patent application Ser. No. 16/774,869, filed on Jan. 28, 2020, which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure generally relates to the technical field of social networks. In particular, the present embodiments are generally directed to managing message retention and deletion. 
     BACKGROUND 
     As the popularity of social networking grows, social networks are expanding their capabilities. To improve ease of use, social networks are integrating more and more functions such that a user may accomplish many or even most of their computer-based tasks within the social network itself. One vision of social networks is that they eventually become a virtual operating system, from which a user seldom finds a need to remove themselves. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced. Some embodiments are illustrated by way of example, and not limitation, in the figures of the accompanying drawings in which: 
         FIG. 1  is a block diagram showing an example messaging system for exchanging data (e.g., messages and associated content) over a network, according to example embodiments. 
         FIG. 2  is a schematic diagram illustrating data which may be stored in the database of a messaging server system, according to example embodiments. 
         FIG. 3  is a schematic diagram illustrating a structure of a message generated by a messaging client application for communication, according to example embodiments. 
         FIG. 4  is a block diagram showing an example message deletion system, according to example embodiments. 
         FIG. 5  is a flowchart illustrating example operations of the message deletion system, according to example embodiments. 
         FIG. 6  is a flowchart illustrating example operations of the message deletion system, according to example embodiments. 
         FIG. 7  shows illustrative inputs and outputs of the message deletion system, according to example embodiments. 
         FIG. 8  is a block diagram illustrating a representative software architecture, which may be used in conjunction with various hardware architectures herein described, according to example embodiments. 
         FIG. 9  is a block diagram illustrating components of a machine able to read instructions from a machine-readable medium (e.g., a machine-readable storage medium) and perform any one or more of the methodologies discussed herein, according to example embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The description that follows includes systems, methods, techniques, instruction sequences, and computing machine program products that embody illustrative embodiments of the disclosure. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide an understanding of various embodiments. It will be evident, however, to those skilled in the art, that embodiments may be practiced without these specific details. In general, well-known instruction instances, protocols, structures, and techniques are not necessarily shown in detail. 
     Often, users consume media content, and specifically videos, on their mobile device. Such media content is typically exchanged in chat sessions between users and consumes a great deal of storage resources as videos and images grow in resolution and size. As such, managing the storage resources used to maintain the chat sessions has become of great interest. One way in which the storage resources are managed is by automatic deletion of the messages on a periodic basis. While such automatic deletion generally works well, the automatic deletion is performed on a message basis and consumes a great deal of overhead. Namely, the automatic deletion iterates through every message exchanged in the conversation to determine whether that message meets some deletion criteria. Such iterations through the messages, when done for all the chat sessions managed by the system, can be extremely tedious and time consuming and requires dedicated processing resources. 
     The disclosed embodiments improve the efficiency of using the electronic device by providing a system that automatically deletes messages based on message sent times and/or message read times on a bulk message basis. Specifically, the disclosed system automatically deletes a plurality of messages exchanged in a communication session based on a read time of a given one of the plurality of messages. Namely, the disclosed system determines that a given one of the plurality of messages has been read by a given user of the conversation session. In response, the disclosed system automatically associates prior messages received in the conversation session (those messages received before the given one of the plurality of messages) with the same read time. The disclosed system then employs a deletion policy which deletes messages within a threshold period of time from when the messages are read. As an example, the disclosed system deletes messages 24 hours after they are read. In this way, after the given message is read by the given user, the given message is deleted after the threshold period of time from when the given message was read along with the prior messages. In some cases, when messages are not read within a second threshold period of time, such as after 31 days, the messages are automatically deleted. Deleting a message removes access to the message for any participant or user of the conversation session including the user or participant who initially sent the message. This way, when a recipient user reads a message, the message (and all prior messages received in the conversation session) is deleted for the recipient and the sender of the message in the conversation session after the threshold period of time from when the message is read. 
     Rather than individually determining the read times for the prior messages, the disclosed system assumes that all the prior messages have been read at the same read time as the latest message that is read and associates such prior messages with the same read time. This increases the efficiencies of the electronic device by reducing processing times and storage resources needed to accomplish a task. In particular, by not having to track when each message in a conversation is read to automatically delete such messages, bulk deletion of messages can be performed more efficiently by assigning a bulk read time to all messages based on a read time of the last read message and deleting the messages based on the bulk read time. This reduces the device resources (e.g., processor cycles, memory, and power usage) needed to accomplish a task with the device. 
       FIG. 1  is a block diagram showing an example messaging system  100  for exchanging data (e.g., messages and associated content) over a network  106 . The messaging system  100  includes multiple client devices  102 , each of which hosts a number of applications, including a messaging client application  104  and a third-party application  105 . Each messaging client application  104  is communicatively coupled to other instances of the messaging client application  104 , the third-party application  105 , and a messaging server system  108  via a network  106  (e.g., the Internet). 
     Accordingly, each messaging client application  104  and third-party application  105  is able to communicate and exchange data with another messaging client application  104  and third-party application(s)  105  and with the messaging server system  108  via the network  106 . The data exchanged between messaging client applications  104 , third-party applications  105 , and the messaging server system  108  includes functions (e.g., commands to invoke functions) and payload data (e.g., text, audio, video, or other multimedia data). Any disclosed communications between the messaging client application  104  and the third-party application(s)  105  can be transmitted directly from the messaging client application  104  to the third-party application(s)  105  and/or indirectly (e.g., via one or more servers) from the messaging client application  104  to the third-party application(s)  105 . 
     The third-party application(s)  105  and the messaging client application  104  are applications that include a set of functions that allow the client device  102  to access a message deletion system  124 . The third-party application  105  is an application that is separate and distinct from the messaging client application  104 . The third-party application(s)  105  are downloaded and installed by the client device  102  separately from the messaging client application  104 . In some implementations, the third-party application(s)  105  are downloaded and installed by the client device  102  before or after the messaging client application  104  is downloaded and installed. The third-party application  105  is an application that is provided by an entity or organization that is different from the entity or organization that provides the messaging client application  104 . The third-party application  105  is an application that can be accessed by a client device  102  using separate login credentials than the messaging client application  104 . Namely, the third-party application  105  can maintain a first user account and the messaging client application  104  can maintain a second user account. For example, the third-party application  105  can be a social networking application, a dating application, a ride or car sharing application, a shopping application, a trading application, a gaming application, or an imaging application. 
     The messaging server system  108  provides server-side functionality via the network  106  to a particular messaging client application  104 . While certain functions of the messaging system  100  are described herein as being performed by either a messaging client application  104  or by the messaging server system  108 , it will be appreciated that the location of certain functionality either within the messaging client application  104  or the messaging server system  108  is a design choice. For example, it may be technically preferable to initially deploy certain technology and functionality within the messaging server system  108 , but to later migrate this technology and functionality to the messaging client application  104  where a client device  102  has a sufficient processing capacity. 
     The messaging server system  108  supports various services and operations that are provided to the messaging client application  104 . Such operations include transmitting data to, receiving data from, and processing data generated by the messaging client application  104 . This data may include message content, client device information, geolocation information, media annotation and overlays, virtual objects, message content persistence conditions, social network information, and live event information, as examples. Data exchanges within the messaging system  100  are invoked and controlled through functions available via user interfaces (UIs) of the messaging client application  104 . 
     Turning now specifically to the messaging server system  108 , an API server  110  is coupled to, and provides a programmatic interface to, an application server  112 . The application server  112  is communicatively coupled to a database server  118 , which facilitates access to a database  120  in which is stored data associated with messages processed by the application server  112 . 
     Dealing specifically with the API server  110 , this server  110  receives and transmits message data (e.g., commands and message payloads) between the client device  102  and the application server  112 . Specifically, the API server  110  provides a set of interfaces (e.g., routines and protocols) that can be called or queried by the messaging client application  104  and the third-party application  105  in order to invoke functionality of the application server  112 . The API server  110  exposes various functions supported by the application server  112 , including account registration; login functionality; the sending of messages, via the application server  112 , from a particular messaging client application  104  to another messaging client application  104  or third-party application  105 ; the sending of media files (e.g., images or video) from a messaging client application  104  to the messaging server application  114 , and for possible access by another messaging client application  104  or third-party application  105 ; the setting of a collection of media data (e.g., story); the retrieval of such collections; the retrieval of a list of friends of a user of a client device  102 ; the retrieval of messages and content; the adding and deleting of friends to a social graph; the location of friends within a social graph; access to user conversation data; access to avatar information stored on messaging server system  108 ; and opening an application event (e.g., relating to the messaging client application  104 ). 
     The application server  112  hosts a number of applications and subsystems, including a messaging server application  114 , an image processing system  116 , a social network system  122 , and the message deletion system  124 . The messaging server application  114  implements a number of message processing technologies and functions, particularly related to the aggregation and other processing of content (e.g., textual and multimedia content) included in messages received from multiple instances of the messaging client application  104 . As will be described in further detail, the text and media content from multiple sources may be aggregated into collections of content (e.g., called stories or galleries). These collections are then made available, by the messaging server application  114 , to the messaging client application  104 . Other processor- and memory-intensive processing of data may also be performed server-side by the messaging server application  114 , in view of the hardware requirements for such processing. 
     The application server  112  also includes an image processing system  116  that is dedicated to performing various image processing operations, typically with respect to images or video received within the payload of a message at the messaging server application  114 . A portion of the image processing system  116  may also be implemented by the message deletion system  124 . 
     The social network system  122  supports various social networking functions and services and makes these functions and services available to the messaging server application  114 . To this end, the social network system  122  maintains and accesses an entity graph within the database  120 . Examples of functions and services supported by the social network system  122  include the identification of other users of the messaging system  100  with which a particular user has relationships or is “following” and also the identification of other entities and interests of a particular user. Such other users may be referred to as the user&#39;s friends. Social network system  122  may access location information associated with each of the user&#39;s friends to determine where they live or are currently located geographically. Social network system  122  may maintain a location profile for each of the user&#39;s friends indicating the geographical location where the user&#39;s friends live. 
     The message deletion system  124  manages storage and retention policies for messages exchanged in a communication session. For example, the message deletion system  124  may determine when a given message is read by a recipient in a communication session. In response, the message deletion system  124  starts a timer for deleting the given message from the communication session. In some cases, the message deletion system  124  deletes the given message and any message received prior to the given message in the communication session automatically when the timer reaches a threshold amount of time (e.g., after 24 hours). The message deletion system  124  stores messages that are received in the conversation session and automatically deletes the messages if they are not read within 31 days from when they are received. This way, the message deletion system  124  allows users in a conversation session to exchange messages with each other but may only allow the users to see the messages in the conversation session for 24 hours after one or all of the users in the conversation session read the latest message or for 31 days after the messages are received. 
     In some embodiments, the message deletion system  124  receives a plurality of messages directed to a second user from a first user in a conversation session. The message deletion system  124  stores the messages with an unread status indicator and also stores a timestamp indicating when each message was received from the first user. The second user may launch the messaging application to access the conversation session. In response, the messaging application of the second user&#39;s device sends a request to the message deletion system  124  to receive messages that follow a certain timestamp. For example, the second user&#39;s device determines when the last time the messaging application was opened by the second user. The second user&#39;s device requests that the message deletion system  124  send to the second user&#39;s device any message that was sent by the first user after that last time the messaging application was opened by the second user. After the second user&#39;s device receives the messages sent by the first user, the messages are displayed in the conversation session on the messaging application to the second user. In some cases, only the last message that was sent by the first user is shown and the second user may scroll up to view previous messages sent by the first user. 
     Once the last message is displayed to the second user, the second user&#39;s device records the read time of the last message. The second user&#39;s device sends a notification to the message deletion system  124  indicating the read time for the last message. In response to receiving the notification, the message deletion system  124  stores the read time for all of the messages stored in the message deletion system  124  that are marked as unread (e.g., any message the does not currently have a read time stored). In this way, when the last message is read by the second user and regardless of whether the second user also reads prior messages that the second user&#39;s device receives, all the messages currently delivered to the second user are marked as read with the same read time as the latest message the second user has viewed in the conversation session on the messaging application. 
     The server compares the current time to the read time of each message the message deletion system  124  stores. When the difference between the current time and the read time corresponds to a threshold amount of time (e.g., reaches 24 hours), the message deletion system  124  automatically deletes the messages associated with that particular read time. In some embodiments, the message deletion system  124  compares the current time only to the oldest read time of the messages stored by the message deletion system  124 . This way, the sever need not compare the current time to all of the read times continuously. Once the difference between the read time of the oldest read message and the current time corresponds to the threshold amount of time, the message deletion system  124  traverses or iterates through other messages to identify a set of messages associated with the same read time. The message deletion system  124  then automatically deletes all the messages that are associated with the same read time. 
     In some embodiments, the message deletion system  124  starts a timer when a given message is read by a user of the conversation session. When the timer reaches the threshold amount of time (e.g., 24 hours), the message deletion system  124  automatically deletes that message and any message received prior to the given message. 
     In some embodiments, certain messages are marked as to be saved based on specific input from a user or because the messages meet some criteria. In such cases, the message deletion system  124  avoids automatically deleting such messages even though the elapsed time since they have been read exceeds the threshold amount time (e.g., messages that would automatically be deleted after 24 hours from when they are read, are retained if the messages are marked to be saved). 
     In some embodiments, the message deletion system  124  compares the oldest receive time of the messages exchanged in the conversation session to the current time. In some cases, such messages are those that are marked as unread. When a difference between the oldest receive time and the current time exceeds another threshold amount of time (e.g., exceeds 31 days), the message deletion system  124  automatically deletes such messages that are unread. When messages are deleted, none of the users or participants in the communication session (e.g., in the chat session) can view the contents of the messages. 
     The application server  112  is communicatively coupled to a database server  118 , which facilitates access to a database  120  in which is stored data associated with messages processed by the messaging server application  114 . Database  120  may be a third-party database. For example, the application server  112  may be associated with a first entity, and the database  120  or a portion of the database  120  may be associated with and hosted by a second, different entity. In some implementations, database  120  stores user data that the first entity collects about various each of the users of a service provided by the first entity. For example, the user data includes user names, passwords, addresses, friends, activity information, preferences, videos or content consumed by the user, and so forth. 
       FIG. 2  is a schematic diagram  200  illustrating data, which may be stored in the database  120  of the messaging server system  108 , according to certain example embodiments. While the content of the database  120  is shown to comprise a number of tables, it will be appreciated that the data could be stored in other types of data structures (e.g., as an object-oriented database). 
     The database  120  includes message data stored within a message table  214 . An entity table  202  stores entity data, including an entity graph  204 . Entities for which records are maintained within the entity table  202  may include individuals, corporate entities, organizations, objects, places, events, and so forth. Regardless of type, any entity regarding which the messaging server system  108  stores data may be a recognized entity. Each entity is provided with a unique identifier, as well as an entity type identifier (not shown). 
     The entity graph  204  stores information regarding relationships and associations between entities. Such relationships may be social, professional (e.g., work at a common corporation or organization), interest-based, or activity-based, merely for example. 
     Message table  214  may store a collection of conversations between a user and one or more friends or entities. Message table  214  may include various attributes of each conversation, such as the list of participants, the size of the conversation (e.g., number of users and/or number of messages), the chat color of the conversation, a unique identifier for the conversation, and any other conversation related feature(s). 
     The database  120  also stores annotation data, in the example form of filters, in an annotation table  212 . Database  120  also stores annotated content received in the annotation table  212 . Filters for which data is stored within the annotation table  212  are associated with and applied to videos (for which data is stored in a video table  210 ) and/or images (for which data is stored in an image table  208 ). Filters, in one example, are overlays that are displayed as overlaid on an image or video during presentation to a recipient user. Filters may be of various types, including user-selected filters from a gallery of filters presented to a sending user by the messaging client application  104  when the sending user is composing a message. Other types of filters include geolocation filters (also known as geo-filters), which may be presented to a sending user based on geographic location. For example, geolocation filters specific to a neighborhood or special location may be presented within a UI by the messaging client application  104 , based on geolocation information determined by a Global Positioning System (GPS) unit of the client device  102 . Another type of filter is a data filter, which may be selectively presented to a sending user by the messaging client application  104 , based on other inputs or information gathered by the client device  102  during the message creation process. Examples of data filters include current temperature at a specific location, a current speed at which a sending user is traveling, battery life for a client device  102 , or the current time. 
     Other annotation data that may be stored within the image table  208  is so-called “lens” data. A “lens” may be a real-time special effect and sound that may be added to an image or a video. 
     As mentioned above, the video table  210  stores video data which, in one embodiment, is associated with messages for which records are maintained within the message table  214 . Similarly, the image table  208  stores image data associated with messages for which message data is stored in the entity table  202 . The entity table  202  may associate various annotations from the annotation table  212  with various images and videos stored in the image table  208  and the video table  210 . 
     Message read time(s)  207  stores various information about messages exchanged in a communication session. Such information includes whether the messages have been read or unread, the read time, the receive time, and so forth. Based on the message read time(s)  207  information, the message deletion system  124  determines whether to automatically delete certain messages in a communication session. 
     A story table  206  stores data regarding collections of messages and associated image, video, or audio data, which are compiled into a collection (e.g., a story or a gallery). The creation of a particular collection may be initiated by a particular user (e.g., each user for which a record is maintained in the entity table  202 ). A user may create a “personal story” in the form of a collection of content that has been created and sent/broadcast by that user. To this end, the UI of the messaging client application  104  may include an icon that is user-selectable to enable a sending user to add specific content to his or her personal story. 
     A collection may also constitute a “live story,” which is a collection of content from multiple users that is created manually, automatically, or using a combination of manual and automatic techniques. For example, a “live story” may constitute a curated stream of user-submitted content from various locations and events. Users whose client devices  102  have location services enabled and are at a common location event at a particular time may, for example, be presented with an option, via a UI of the messaging client application  104 , to contribute content to a particular live story. The live story may be identified to the user by the messaging client application  104  based on his or her location. The end result is a “live story” told from a community perspective. 
     A further type of content collection is known as a “location story,” which enables a user whose client device  102  is located within a specific geographic location (e.g., on a college or university campus) to contribute to a particular collection. In some embodiments, a contribution to a location story may require a second degree of authentication to verify that the end user belongs to a specific organization or other entity (e.g., is a student on the university campus). 
       FIG. 3  is a schematic diagram illustrating a structure of a message  300 , according to some embodiments, generated by a messaging client application  104  for communication to a further messaging client application  104  or the messaging server application  114 . The content of a particular message  300  is used to populate the message table  214  stored within the database  120 , accessible by the messaging server application  114 . Similarly, the content of a message  300  is stored in memory as “in-transit” or “in-flight” data of the client device  102  or the application server  112 . The message  300  is shown to include the following components:
     A message identifier  302 : a unique identifier that identifies the message  300 .   A message text payload  304 : text, to be generated by a user via a UI of the client device  102  and that is included in the message  300 .   A message image payload  306 : image data, captured by a camera component of a client device  102  or retrieved from memory of a client device  102 , and that is included in the message  300 .   A message video payload  308 : video data, captured by a camera component or retrieved from a memory component of the client device  102  and that is included in the message  300 .   A message audio payload  310 : audio data, captured by a microphone or retrieved from the memory component of the client device  102 , and that is included in the message  300 .   Message annotations  312 : annotation data (e.g., filters, stickers, or other enhancements) that represents annotations to be applied to message image payload  306 , message video payload  308 , or message audio payload  310  of the message  300 .   A message duration parameter  314 : parameter value indicating, in seconds, the amount of time for which content of the message (e.g., the message image payload  306 , message video payload  308 , message audio payload  310 ) is to be presented or made accessible to a user via the messaging client application  104 .   A message geolocation parameter  316 : geolocation data (e.g., latitudinal and longitudinal coordinates) associated with the content payload of the message. Multiple message geolocation parameter  316  values may be included in the payload, with each of these parameter values being associated with respect to content items included in the content (e.g., a specific image within the message image payload  306 , or a specific video in the message video payload  308 ).   A message story identifier  318 : identifier value identifying one or more content collections (e.g., “stories”) with which a particular content item in the message image payload  306  of the message  300  is associated. For example, multiple images within the message image payload  306  may each be associated with multiple content collections using identifier values.   A message tag  320 : each message  300  may be tagged with multiple tags, each of which is indicative of the subject matter of content included in the message payload. For example, where a particular image included in the message image payload  306  depicts an animal (e.g., a lion), a tag value may be included within the message tag  320  that is indicative of the relevant animal. Tag values may be generated manually, based on user input, or may be automatically generated using, for example, image recognition.   A message sender identifier  322 : an identifier (e.g., a messaging system identifier, email address, or device identifier) indicative of a user of the client device  102  on which the message  300  was generated and from which the message  300  was sent.   A message receiver identifier  324 : an identifier (e.g., a messaging system identifier, email address, or device identifier) indicative of user(s) of the client device  102  to which the message  300  is addressed. In the case of a conversation between multiple users, the identifier may indicate each user involved in the conversation.   

     The contents (e.g., values) of the various components of message  300  may be pointers to locations in tables within which content data values are stored. For example, an image value in the message image payload  306  may be a pointer to (or address of) a location within an image table  208 . Similarly, values within the message video payload  308  may point to data stored within a video table  210 , values stored within the message annotations  312  may point to data stored in an annotation table  212 , values stored within the message story identifier  318  may point to data stored in a story table  206 , and values stored within the message sender identifier  322  and the message receiver identifier  324  may point to user records stored within an entity table  202 . 
       FIG. 4  is a block diagram showing an example message deletion system  124 , according to example embodiments. Message deletion system  124  includes a communication session module  414 , a read detection module  416 , and a message deletion module  418 . The communication session module  414  enables users to engage in a communication session to exchange messages with each other. In some cases, the communication session includes a group of three or more users in which case any message sent by one user is viewable by the other two users in the group. In some cases, the communication session includes only two users where one user sends messages to another user and vice versa. 
     After initiating a communication session using the communication session module  414 , messages are transferred between users of the communication session using the communication session module  414 . For example, the communication session module  414  receives a message from a first user in the communication session and marks the message for transmission to a second user in the communication session. The communication session module  414  stores the message along with various information indicating the recipient, the communication session identifier, and the receive time stamp. When the second user logs into the message application, the communication session module  414  receives an identifier of the second user and determines whether any messages that have not been delivered yet to the second user and that are intended for the second user to receive. In some cases, the communication session module  414  receives a last update timestamp from the second user. The communication session module  414  searches the receive time of all the messages that are intended for receipt by the second user. The communication session module  414  selects those messages that have a receive time that is later than the last update timestamp. The communication session module  414  then sends all of the selected messages to the user device of the second user for presentation in the communication session of the message client application  104 . 
     The second user may open the communication session in the messaging client application  104 . Once a message is displayed in the communication session for the second user, the messaging client application  104  stores a read time for the message that is displayed. The messaging client application  104  sends a notification to the read detection module  416  with an identifier of the communication session and an identifier of the message that has been read and the read time of the message. The read detection module  416  then identifies all the messages that are associated with the same communication session identifier that do not have a read time associated with them. As an example, the read detection module  416  identifies all the unread messages that are associated with the communication session identifier received in the notification. The read detection module  416  filters the identified unread messages for those messages that have a receive time that precedes the receive time of the message identified by the identifier received in the notification. Namely, the read detection module  416  finds all the messages that were sent to the second user before the message that has most recently been read by the second user. 
     The read detection module  416  updates the read time associated with the identified message received in the notification with the read time indicated in the notification. The read detection module  416  also simultaneously or thereafter updates the read times associated with all the filtered unread messages (or all the messages for which a read time is not yet stored and which were received from the first user before the message most recently read by the second user) with the same read time that is indicated in the notification for the message most recently read by the second user. This way, once the second user reads a first message in a communication session, all the messages that were sent to the second user from the first user before the first message are also marked as being read at the same time as the first message. In some cases, the read times are presented to the users in a display of the communication session (e.g., next to the contents of the messages and/or in a separate display in response to receiving a user request to view the read times). 
     In some embodiments, the storage of a read time for one or more messages in a communication session, initiates a deletion timer for the one or more messages. Specifically, the message deletion module  418  automatically deletes messages that have been read 24 hours after they are read. Namely, once the deletion timer reaches a specified threshold time period (e.g., 24 hours), the message deletion module  418  deletes the messages and removes them from the communication session. As an example, message deletion module  418  compares the current time to the read time of each message of the communication session. When the difference between the current time and the read time corresponds to a threshold amount of time (e.g., reaches 24 hours), the message deletion module  418  automatically deletes the messages associated with that particular read time. 
     In some embodiments, the message deletion module  418  compares the current time only to the oldest read time of the messages that are in the communication session. This way, the message deletion module  418  need not compare the current time to all of the read times continuously. Once the difference between the read time of the oldest read message and the current time corresponds to the threshold amount of time, the message deletion module  418  traverses or iterates through other messages to identify a set of messages associated with the same read time. The message deletion module  418  then automatically deletes all the messages that are associated with the same read time. 
     In some embodiments, certain messages are marked as to be saved based on specific input from a user or because the messages meet some criteria. In such cases, the message deletion module  418  avoids automatically deleting such messages even though the elapsed time since they have been read exceeds the threshold amount time (e.g., messages that would automatically be deleted after 24 hours from when they are read, are retained if the messages are marked to be saved). 
     In some embodiments, the message deletion module  418  compares the oldest receive time of the messages exchanged in the communication session to the current time. In some cases, such messages are those that are marked as unread. When a difference between the oldest receive time and the current time exceeds another threshold amount of time (e.g., exceeds 31 days), the message deletion module  418  automatically deletes such messages that are unread. When messages are deleted, none of the users or participants in the communication session (e.g., in the chat session) can view the contents of the messages. As such, the message deletion module  418  is configured to delete all prior messages received in a communication session before a given message 24-hours after only the given message has been read by one or all participants in the communication session. Namely, a user need not read all of the messages in the communication session to trigger the 24-hour deletion. The message deletion module  418  is also configured to delete any message that has been received in the communication session more than 31 days ago regardless of whether the message was read or not. 
     As an example, a recipient may receive 30 messages in a communication session. The recipient may read the 27 th  message at a particular time (e.g., 7 AM) and may read the 22nd-26 th  messages at a later time (e.g., 8 AM) than the particular time. However, because the 22nd-26 th  messages were received prior to the 27 th  message, they are associated with the same read time as the 27 th  message (e.g., 7 AM). As such, the message deletion module  418  deletes messages 1-27 24 hours after the 27 th  message is read (e.g., messages 1-27 are deleted the next day at 7 AM even though messages 22-26 were read at 8 AM on the previous day—less than 24 hours after the 27 th  message was read). Messages 28-30 which follow the 27 th  message and which have not yet been read, are not automatically deleted until 24 hours after they are read by the recipient or 31 days after the time stamp of when they were received from a sender by the communication session. 
       FIG. 5  is a flowchart illustrating example operations of the message deletion system  124  in performing process  500 , according to example embodiments. The process  500  may be embodied in computer-readable instructions for execution by one or more processors such that the operations of the process  500  may be performed in part or in whole by the functional components of the messaging server system  108  and/or third-party application  105 ; accordingly, the process  500  is described below by way of example with reference thereto. However, in other embodiments, at least some of the operations of the process  500  may be deployed on various other hardware configurations. The process  500  is therefore not intended to be limited to the messaging server system  108  and can be implemented in whole, or in part, by any other component. Some or all of the operations of process  500  can be in parallel, out of order, or entirely omitted. 
     At operation  501 , the message deletion system  124  establishes a communication session between a plurality of users. For example, the communication session module  414  receives input from a first user operating a first client device  102  to send a message to one or more other users. In response, the communication session module  414  establishes a chat session that provides a display to the first user and the one or more other users for enabling the users to see messages exchanged between the users and send messages to each other. 
     At operation  502 , the message deletion system  124  receives a plurality of messages in the communication session. For example, the communication session module  414  receives messages from the first user and/or the one or more other users that are engaged in the communication session. The first user can type in a message or multiple messages and send the messages in the communication session graphical user interface so the other users can see the messages. When the user sends the messages the communication session module  414  receives the messages and stores them. 
     At operation  503 , the message deletion system  124  determines that a first message of the plurality of messages has been read by a first user of the plurality of users at a read time. For example, the message deletion system  124  receives an indication (e.g., a read time) from a user device of the first user when the first user opens the communication session and views the first message (e.g., the last message) that was exchanged or sent in the communication session by one or more other participants or users in the communication session. 
     At operation  504 , the message deletion system  124  automatically associates the read time with a second of the plurality of messages that precedes the first message in the communication session. For example, the message deletion system  124  identifies a set of messages that have earlier timestamps than the message that the user has read and that have also not yet been read by the first user and assigns the same read time as that which was assigned to the first message. 
     At operation  505 , the message deletion system  124  automatically deletes the first and second messages in response to determining that an elapsed time measured from the read time associated with the first and second messages corresponds to a threshold time period. For example, when a 24-hour period of time has elapsed since the read time associated with the messages, the message deletion system  124  automatically deletes the messages associated with that read time. 
       FIG. 6  is a flowchart illustrating example operations of the message deletion system  124  in performing process  600 , according to example embodiments. The process  600  may be embodied in computer-readable instructions for execution by one or more processors such that the operations of the process  600  may be performed in part or in whole by the functional components of the messaging server system  108  and/or third-party application  105 ; accordingly, the process  600  is described below by way of example with reference thereto. However, in other embodiments, at least some of the operations of the process  600  may be deployed on various other hardware configurations. The process  600  is therefore not intended to be limited to the messaging server system  108  and can be implemented in whole, or in part, by any other component. Some or all of the operations of process  600  can be in parallel, out of order, or entirely omitted. 
     At operation  601 , the message deletion system  124  determines a receive time indicating when a message was received in a communication session. For example, the message deletion system  124  associates a timestamp with each message that is received in the communication session indicating when the message was received (or sent by another user in the communication session) 
     At operation  602 , the message deletion system  124  detects that the message was read by a recipient in the communication session. For example, the message deletion system  124  receives an indication (e.g., a read time) from a user device of the first user when the first user opens the communication session and views the first message (e.g., the last message) that was exchanged or sent in the communication session by one or more other participants or users in the communication session. 
     At operation  603 , the message deletion system  124  automatically deletes the message after a first threshold time period from when the message was read. For example, when a 24-hour period of time has elapsed since the read time associated with the messages, the message deletion system  124  automatically deletes the messages associated with that read time. 
     At operation  604 , the message deletion system  124  detects that the message was not read by the recipient within a second threshold time period from when the message was received. For example, the message deletion system  124  determines that the timestamp of a given message is more than 31 days old (e.g., the timestamp exceeds a 31 day period of time). The message deletion system  124  may continuously or periodically process the receive timestamps of messages that are exchanged in the communication session to identify messages that have been received more than 31 days earlier than the present time. 
     At operation  605 , the message deletion system  124  automatically deletes the message after the second threshold time period from when the message was received. For example, the message deletion system  124  automatically deletes any message that was received more than 31 days before the current time regardless of whether that message was read or not. 
       FIG. 7  includes illustrative inputs and outputs of the message deletion system  124 , according to example embodiments. The message deletion system  124  causes presentation of a graphical user interface  710  on a messaging client application  104 . The graphical user interface  710  includes a display of messages that are part of a communication session between multiple users (e.g., John, Mark and Jennifer). The graphical user interface  710  is presented to given user  714  (e.g., Jennifer). The graphical user interface  710  indicates the read time  716  for each message indicating when the given user  714  has read the messages. In some cases, once the given user  714  logs in and downloads the messages that are part of the communication session (e.g., at 9:41 AM), the latest message is automatically presented to the given user  714 . The given user  714  can scroll up to view earlier messages. Even though the earlier messages are not viewed at the same time as the latest message (e.g., the given user  714  scrolls up to view the earlier messages at a later time), all the messages are associated with the same read time (e.g., 9:41 AM) as the time at which the latest message was read by the given user  714 . A notification  720  is presented to the given user  714  indicating the deletion policy (e.g., the messages are deleted automatically 24 hours after they are read or 31 days after they are sent regardless of when they are read or if they are read at all). In this case, the messages presented in the communication session and all prior messages to those presented in the communication session will be automatically deleted 24 hours after 9:41 AM (e.g., the next day at 9:41 AM). 
       FIG. 8  is a block diagram illustrating an example software architecture  806 , which may be used in conjunction with various hardware architectures herein described.  FIG. 8  is a non-limiting example of a software architecture and it will be appreciated that many other architectures may be implemented to facilitate the functionality described herein. The software architecture  806  may execute on hardware such as machine  900  of  FIG. 9  that includes, among other things, processors  904 , memory  914 , and input/output (I/O) components  918 . A representative hardware layer  852  is illustrated and can represent, for example, the machine  900  of  FIG. 9 . The representative hardware layer  852  includes a processing unit  854  having associated executable instructions  804 . Executable instructions  804  represent the executable instructions of the software architecture  806 , including implementation of the methods, components, and so forth described herein. The hardware layer  852  also includes memory and/or storage modules memory/storage  856 , which also have executable instructions  804 . The hardware layer  852  may also comprise other hardware  858 . 
     In the example architecture of  FIG. 8 , the software architecture  806  may be conceptualized as a stack of layers where each layer provides particular functionality. For example, the software architecture  806  may include layers such as an operating system  802 , libraries  820 , frameworks/middleware  818 , applications  816 , and a presentation layer  814 . Operationally, the applications  816  and/or other components within the layers may invoke API calls  808  through the software stack and receive messages  812  in response to the API calls  808 . The layers illustrated are representative in nature and not all software architectures have all layers. For example, some mobile or special purpose operating systems may not provide a frameworks/middleware  818 , while others may provide such a layer. Other software architectures may include additional or different layers. 
     The operating system  802  may manage hardware resources and provide common services. The operating system  802  may include, for example, a kernel  822 , services  824 , and drivers  826 . The kernel  822  may act as an abstraction layer between the hardware and the other software layers. For example, the kernel  822  may be responsible for memory management, processor management (e.g., scheduling), component management, networking, security settings, and so on. The services  824  may provide other common services for the other software layers. The drivers  826  are responsible for controlling or interfacing with the underlying hardware. For instance, the drivers  826  include display drivers, camera drivers, Bluetooth® drivers, flash memory drivers, serial communication drivers (e.g., Universal Serial Bus (USB) drivers), Wi-Fi® drivers, audio drivers, power management drivers, and so forth depending on the hardware configuration. 
     The libraries  820  provide a common infrastructure that is used by the applications  816  and/or other components and/or layers. The libraries  820  provide functionality that allows other software components to perform tasks in an easier fashion than to interface directly with the underlying operating system  802  functionality (e.g., kernel  822 , services  824  and/or drivers  826 ). The libraries  820  may include system libraries  844  (e.g., C standard library) that may provide functions such as memory allocation functions, string manipulation functions, mathematical functions, and the like. In addition, the libraries  820  may include API libraries  846  such as media libraries (e.g., libraries to support presentation and manipulation of various media format such as MPEG4, H.264, MP3, AAC, AMR, JPG, PNG), graphics libraries (e.g., an OpenGL framework that may be used to render two-dimensional and three-dimensional in a graphic content on a display), database libraries (e.g., SQLite that may provide various relational database functions), web libraries (e.g., WebKit that may provide web browsing functionality), and the like. The libraries  820  may also include a wide variety of other libraries  848  to provide many other APIs to the applications  816  and other software components/modules. 
     The frameworks/middleware  818  (also sometimes referred to as middleware) provide a higher-level common infrastructure that may be used by the applications  816  and/or other software components/modules. For example, the frameworks/middleware  818  may provide various graphical user interface functions, high-level resource management, high-level location services, and so forth. The frameworks/middleware  818  may provide a broad spectrum of other APIs that may be utilized by the applications  816  and/or other software components/modules, some of which may be specific to a particular operating system  802  or platform. 
     The applications  816  include built-in applications  838  and/or third-party applications  840 . Examples of representative built-in applications  838  may include, but are not limited to, a contacts application, a browser application, a book reader application, a location application, a media application, a messaging application, and/or a game application. Third-party applications  840  may include an application developed using the ANDROID™ or IOS™ software development kit (SDK) by an entity other than the vendor of the particular platform, and may be mobile software running on a mobile operating system such as IOS™, ANDROID™, WINDOWS® Phone, or other mobile operating systems. The third-party applications  840  may invoke the API calls  808  provided by the mobile operating system (such as operating system  802 ) to facilitate functionality described herein. 
     The applications  816  may use built-in operating system functions (e.g., kernel  822 , services  824 , and/or drivers  826 ), libraries  820 , and frameworks/middleware  818  to create UIs to interact with users of the system. Alternatively, or additionally, in some systems, interactions with a user may occur through a presentation layer, such as presentation layer  814 . In these systems, the application/component “logic” can be separated from the aspects of the application/component that interact with a user. 
       FIG. 9  is a block diagram illustrating components of a machine  900 , according to some example embodiments, able to read instructions from a machine-readable medium (e.g., a machine-readable storage medium) and perform any one or more of the methodologies discussed herein. Specifically,  FIG. 9  shows a diagrammatic representation of the machine  900  in the example form of a computer system, within which instructions  910  (e.g., software, a program, an application, an applet, an app, or other executable code) for causing the machine  900  to perform any one or more of the methodologies discussed herein may be executed. As such, the instructions  910  may be used to implement modules or components described herein. The instructions  910  transform the general, non-programmed machine  900  into a particular machine  900  programmed to carry out the described and illustrated functions in the manner described. In alternative embodiments, the machine  900  operates as a standalone device or may be coupled (e.g., networked) to other machines. In a networked deployment, the machine  900  may operate in the capacity of a server machine or a client machine in a server-client network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine  900  may comprise, but not be limited to, a server computer, a client computer, a personal computer (PC), a tablet computer, a laptop computer, a netbook, a set-top box (STB), a personal digital assistant (PDA), an entertainment media system, a cellular telephone, a smart phone, a mobile device, a wearable device (e.g., a smart watch), a smart home device (e.g., a smart appliance), other smart devices, a web appliance, a network router, a network switch, a network bridge, or any machine capable of executing the instructions  910 , sequentially or otherwise, that specify actions to be taken by machine  900 . Further, while only a single machine  900  is illustrated, the term “machine” shall also be taken to include a collection of machines that individually or jointly execute the instructions  910  to perform any one or more of the methodologies discussed herein. 
     The machine  900  may include processors  904 , memory/storage  906 , and I/O components  918 , which may be configured to communicate with each other such as via a bus  902 . In an example embodiment, the processors  904  (e.g., a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a radio-frequency integrated circuit (RFIC), another processor, or any suitable combination thereof) may include, for example, a processor  908  and a processor  912  that may execute the instructions  910 . The term “processor” is intended to include multi-core processors  904  that may comprise two or more independent processors (sometimes referred to as “cores”) that may execute instructions  910  contemporaneously. Although  FIG. 9  shows multiple processors  904 , the machine  900  may include a single processor  908  with a single core, a single processor  908  with multiple cores (e.g., a multi-core processor), multiple processors  908 ,  912  with a single core, multiple processors  908 ,  912  with multiple cores, or any combination thereof. 
     The memory/storage  906  may include a memory  914 , such as a main memory, or other memory storage, and a storage unit  916 , both accessible to the processors  904  such as via the bus  902 . The storage unit  916  and memory  914  store the instructions  910  embodying any one or more of the methodologies or functions described herein. The instructions  910  may also reside, completely or partially, within the memory  914 , within the storage unit  916 , within at least one of the processors  904  (e.g., within the processor&#39;s cache memory), or any suitable combination thereof, during execution thereof by the machine  900 . Accordingly, the memory  914 , the storage unit  916 , and the memory of processors  904  are examples of machine-readable media. 
     The I/O components  918  may include a wide variety of components to receive input, provide output, produce output, transmit information, exchange information, capture measurements, and so on. The specific I/O components  918  that are included in a particular machine  900  will depend on the type of machine. For example, portable machines such as mobile phones will likely include a touch input device or other such input mechanisms, while a headless server machine will likely not include such a touch input device. It will be appreciated that the I/O components  918  may include many other components that are not shown in  FIG. 9 . The I/O components  918  are grouped according to functionality merely for simplifying the following discussion and the grouping is in no way limiting. In various example embodiments, the I/O components  918  may include output components  926  and input components  928 . The output components  926  may include visual components (e.g., a display such as a plasma display panel (PDP), a light emitting diode (LED) display, a liquid crystal display (LCD), a projector, or a cathode ray tube (CRT)), acoustic components (e.g., speakers), haptic components (e.g., a vibratory motor, resistance mechanisms), other signal generators, and so forth. The input components  928  may include alphanumeric input components (e.g., a keyboard, a touch screen configured to receive alphanumeric input, a photo-optical keyboard, or other alphanumeric input components), point-based input components (e.g., a mouse, a touchpad, a trackball, a joystick, a motion sensor, or other pointing instrument), tactile input components (e.g., a physical button, a touch screen that provides location and/or force of touches or touch gestures, or other tactile input components), audio input components (e.g., a microphone), and the like. 
     In further example embodiments, the I/O components  918  may include biometric components  939 , motion components  934 , environmental components  936 , or position components  938  among a wide array of other components. For example, the biometric components  939  may include components to detect expressions (e.g., hand expressions, facial expressions, vocal expressions, body gestures, or eye tracking), measure biosignals (e.g., blood pressure, heart rate, body temperature, perspiration, or brain waves), identify a person (e.g., voice identification, retinal identification, facial identification, fingerprint identification, or electroencephalogram based identification), and the like. The motion components  934  may include acceleration sensor components (e.g., accelerometer), gravitation sensor components, rotation sensor components (e.g., gyroscope), and so forth. The environmental components  936  may include, for example, illumination sensor components (e.g., photometer), temperature sensor components (e.g., one or more thermometer that detect ambient temperature), humidity sensor components, pressure sensor components (e.g., barometer), acoustic sensor components (e.g., one or more microphones that detect background noise), proximity sensor components (e.g., infrared sensors that detect nearby objects), gas sensors (e.g., gas detection sensors to detection concentrations of hazardous gases for safety or to measure pollutants in the atmosphere), or other components that may provide indications, measurements, or signals corresponding to a surrounding physical environment. The position components  938  may include location sensor components (e.g., a GPS receiver component), altitude sensor components (e.g., altimeters or barometers that detect air pressure from which altitude may be derived), orientation sensor components (e.g., magnetometers), and the like. 
     Communication may be implemented using a wide variety of technologies. The I/O components  918  may include communication components  940  operable to couple the machine  900  to a network  937  or devices  929  via coupling  924  and coupling  922 , respectively. For example, the communication components  940  may include a network interface component or other suitable device to interface with the network  937 . In further examples, communication components  940  may include wired communication components, wireless communication components, cellular communication components, near field communication (NFC) components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components to provide communication via other modalities. The devices  929  may be another machine  900  or any of a wide variety of peripheral devices (e.g., a peripheral device coupled via a USB). 
     Moreover, the communication components  940  may detect identifiers or include components operable to detect identifiers. For example, the communication components  940  may include radio frequency identification (RFID) tag reader components, NFC smart tag detection components, optical reader components (e.g., an optical sensor to detect one-dimensional bar codes such as Universal Product Code (UPC) bar code, multi-dimensional bar codes such as Quick Response (QR) code, Aztec code, Data Matrix, Dataglyph, MaxiCode, PDF417, Ultra Code, UCC RSS-2D bar code, and other optical codes), or acoustic detection components (e.g., microphones to identify tagged audio signals). In addition, a variety of information may be derived via the communication components  940 , such as location via Internet Protocol (IP) geo-location, location via Wi-Fi® signal triangulation, location via detecting a NFC beacon signal that may indicate a particular location, and so forth. 
     Glossary: 
     “CARRIER SIGNAL,” in this context, refers to any intangible medium that is capable of storing, encoding, or carrying transitory or non-transitory instructions  910  for execution by the machine  900 , and includes digital or analog communications signals or other intangible medium to facilitate communication of such instructions  910 . Instructions  910  may be transmitted or received over the network  106  using a transitory or non-transitory transmission medium via a network interface device and using any one of a number of well-known transfer protocols. 
     “CLIENT DEVICE,” in this context, refers to any machine  900  that interfaces to a communications network  106  to obtain resources from one or more server systems or other client devices  102 . A client device  102  may be, but is not limited to, a mobile phone, desktop computer, laptop, PDAs, smart phones, tablets, ultra books, netbooks, laptops, multi-processor systems, microprocessor-based or programmable consumer electronics, game consoles, set-top boxes, or any other communication device that a user may use to access a network  106 . 
     “COMMUNICATIONS NETWORK,” in this context, refers to one or more portions of a network  106  that may be an ad hoc network, an intranet, an extranet, a virtual private network (VPN), a local area network (LAN), a wireless LAN (WLAN), a wide area network (WAN), a wireless WAN (WWAN), a metropolitan area network (MAN), the Internet, a portion of the Internet, a portion of the Public Switched Telephone Network (PSTN), a plain old telephone service (POTS) network, a cellular telephone network, a wireless network, a Wi-Fi® network, another type of network, or a combination of two or more such networks. For example, a network  106  or a portion of a network may include a wireless or cellular network and the coupling may be a Code Division Multiple Access (CDMA) connection, a Global System for Mobile communications (GSM) connection, or other type of cellular or wireless coupling. In this example, the coupling may implement any of a variety of types of data transfer technology, such as Single Carrier Radio Transmission Technology (1xRTT), Evolution-Data Optimized (EVDO) technology, General Packet Radio Service (GPRS) technology, Enhanced Data rates for GSM Evolution (EDGE) technology, third Generation Partnership Project (3GPP) including 3G, fourth generation wireless (4G) networks, Universal Mobile Telecommunications System (UMTS), High Speed Packet Access (HSPA), Worldwide Interoperability for Microwave Access (WiMAX), Long Term Evolution (LTE) standard, others defined by various standard setting organizations, other long range protocols, or other data transfer technology. 
     “EPHEMERAL MESSAGE,” in this context, refers to a message  300  that is accessible for a time-limited duration. An ephemeral message may be a text, an image, a video, and the like. The access time for the ephemeral message may be set by the message sender. Alternatively, the access time may be a default setting or a setting specified by the recipient. Regardless of the setting technique, the message  300  is transitory. 
     “MACHINE-READABLE MEDIUM,” in this context, refers to a component, device, or other tangible media able to store instructions  910  and data temporarily or permanently and may include, but is not limited to, random-access memory (RAM), read-only memory (ROM), buffer memory, flash memory, optical media, magnetic media, cache memory, other types of storage (e.g., erasable programmable read-only memory (EEPROM)) and/or any suitable combination thereof. The term “machine-readable medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, or associated caches and servers) able to store instructions  910 . The term “machine-readable medium” shall also be taken to include any medium, or combination of multiple media, that is capable of storing instructions  910  (e.g., code) for execution by a machine  900 , such that the instructions  910 , when executed by one or more processors  904  of the machine  900 , cause the machine  900  to perform any one or more of the methodologies described herein. Accordingly, a “machine-readable medium” refers to a single storage apparatus or device, as well as “cloud-based” storage systems or storage networks that include multiple storage apparatus or devices. The term “machine-readable medium” excludes signals per se. 
     “COMPONENT,” in this context, refers to a device, physical entity, or logic having boundaries defined by function or subroutine calls, branch points, APIs, or other technologies that provide for the partitioning or modularization of particular processing or control functions. Components may be combined via their interfaces with other components to carry out a machine process. A component may be a packaged functional hardware unit designed for use with other components and a part of a program that usually performs a particular function of related functions. Components may constitute either software components (e.g., code embodied on a machine-readable medium) or hardware components. A “hardware component” is a tangible unit capable of performing certain operations and may be configured or arranged in a certain physical manner. In various example embodiments, one or more computer systems (e.g., a standalone computer system, a client computer system, or a server computer system) or one or more hardware components of a computer system (e.g., a processor or a group of processors) may be configured by software (e.g., an application or application portion) as a hardware component that operates to perform certain operations as described herein. 
     A hardware component may also be implemented mechanically, electronically, or any suitable combination thereof. For example, a hardware component may include dedicated circuitry or logic that is permanently configured to perform certain operations. A hardware component may be a special-purpose processor, such as a field-programmable gate array (FPGA) or an ASIC. A hardware component may also include programmable logic or circuitry that is temporarily configured by software to perform certain operations. For example, a hardware component may include software executed by a general-purpose processor  908  or other programmable processor. Once configured by such software, hardware components become specific machines (or specific components of a machine  900 ) uniquely tailored to perform the configured functions and are no longer general-purpose processors  908 . It will be appreciated that the decision to implement a hardware component mechanically, in dedicated and permanently configured circuitry, or in temporarily configured circuitry (e.g., configured by software) may be driven by cost and time considerations. Accordingly, the phrase “hardware component”(or “hardware-implemented component”) should be understood to encompass a tangible entity, be that an entity that is physically constructed, permanently configured (e.g., hardwired), or temporarily configured (e.g., programmed) to operate in a certain manner or to perform certain operations described herein. Considering embodiments in which hardware components are temporarily configured (e.g., programmed), each of the hardware components need not be configured or instantiated at any one instance in time. For example, where a hardware component comprises a general-purpose processor  908  configured by software to become a special-purpose processor, the general-purpose processor  908  may be configured as respectively different special-purpose processors (e.g., comprising different hardware components) at different times. Software accordingly configures a particular processor  908  or processors  904 , for example, to constitute a particular hardware component at one instance of time and to constitute a different hardware component at a different instance of time. 
     Hardware components can provide information to, and receive information from, other hardware components. Accordingly, the described hardware components may be regarded as being communicatively coupled. Where multiple hardware components exist contemporaneously, communications may be achieved through signal transmission (e.g., over appropriate circuits and buses) between or among two or more of the hardware components. In embodiments in which multiple hardware components are configured or instantiated at different times, communications between such hardware components may be achieved, for example, through the storage and retrieval of information in memory structures to which the multiple hardware components have access. For example, one hardware component may perform an operation and store the output of that operation in a memory device to which it is communicatively coupled. A further hardware component may then, at a later time, access the memory device to retrieve and process the stored output. 
     Hardware components may also initiate communications with input or output devices, and can operate on a resource (e.g., a collection of information). The various operations of example methods described herein may be performed, at least partially, by one or more processors  904  that are temporarily configured (e.g., by software) or permanently configured to perform the relevant operations. Whether temporarily or permanently configured, such processors  904  may constitute processor-implemented components that operate to perform one or more operations or functions described herein. As used herein, “processor-implemented component” refers to a hardware component implemented using one or more processors  904 . Similarly, the methods described herein may be at least partially processor-implemented, with a particular processor  908  or processors  904  being an example of hardware. For example, at least some of the operations of a method may be performed by one or more processors  904  or processor-implemented components. Moreover, the one or more processors  904  may also operate to support performance of the relevant operations in a “cloud computing” environment or as a “software as a service” (SaaS). For example, at least some of the operations may be performed by a group of computers (as examples of machines  900  including processors  904 ), with these operations being accessible via a network  106  (e.g., the Internet) and via one or more appropriate interfaces (e.g., an API). The performance of certain of the operations may be distributed among the processors, not only residing within a single machine  900 , but deployed across a number of machines. In some example embodiments, the processors  904  or processor-implemented components may be located in a single geographic location (e.g., within a home environment, an office environment, or a server farm). In other example embodiments, the processors  904  or processor-implemented components may be distributed across a number of geographic locations. 
     “PROCESSOR,” in this context, refers to any circuit or virtual circuit (a physical circuit emulated by logic executing on an actual processor  908 ) that manipulates data values according to control signals (e.g., “commands,” “op codes,” “machine code,” etc.) and which produces corresponding output signals that are applied to operate a machine  900 . A processor  908  may, for example, be a CPU, a RISC processor, a CISC processor, a GPU, a DSP, an ASIC, a RFIC or any combination thereof. A processor  908  may further be a multi-core processor having two or more independent processors  904  (sometimes referred to as “cores”) that may execute instructions  910  contemporaneously. 
     “TIMESTAMP,” in this context, refers to a sequence of characters or encoded information identifying when a certain event occurred, for example giving date and time of day, sometimes accurate to a small fraction of a second. 
     Changes and modifications may be made to the disclosed embodiments without departing from the scope of the present disclosure. These and other changes or modifications are intended to be included within the scope of the present disclosure, as expressed in the following claims.