Patent Publication Number: US-11645235-B2

Title: File system warnings for moves of shared content items

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation and claims the benefit of priority to U.S. application Ser. No. 15/393,684, filed on Dec. 29, 2016, entitled, FILE SYSTEM WARNINGS FOR MOVES OF SHARED CONTENT ITEMS, which is hereby expressly incorporated herein by reference in its entirety. 
    
    
     TECHINCAL FIELD 
     The present technology relates to warnings provided on a computing device to alert a user to possible unintentional actions, and more specifically to file system warnings that warn of possible unintentional actions on locally stored copies of content items shared through a synchronized content management system. 
     BACKGROUND 
     When working in a shared directory of a server, a change of a content item location by one user will affect all other users of the shared directory. When a content item location is unintentionally changed, or worse, when a content item is unintentionally deleted, the unintentional action can have the undesirable consequence of a lost, or deleted content item. Fortunately, many shared directories have access restrictions that prevent at least deletions of content items, and may prevent other changes as well. Even if the shared directory doesn&#39;t have these safeguards, users are generally aware of the shared nature of the directory, and take extra care. However, some technologies can obscure their shared aspects so effectively that users still do make unintentional changes to a shared content item that affect all other users of the shared content item. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-recited and other advantages and features of the present technology will become apparent by reference to specific implementations illustrated in the appended drawings. A person of ordinary skill in the art will understand that these drawings only show some examples of the present technology and would not limit the scope of the present technology to these examples. Furthermore, the skilled artisan will appreciate the principles of the present technology as described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
         FIG.  1    shows an example of a content management system and client devices; 
         FIG.  2    shows an example method embodiment; 
         FIG.  3    shows an example source file system path and an example destination file system path; and 
         FIG.  4    shows an example of a system for implementing certain aspects of the present technology. 
     
    
    
     DETAILED DESCRIPTION 
     Various examples of the present technology are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the present technology. 
     The disclosed technology addresses the need in the art to provide warnings to users of a shared collection when users attempt to move or delete a shared content item within the shared collection. This need is even greater in the context of a synchronized content management system wherein user accounts can access shared collections directly from within their file system on their client device. In such a context, some users assume that certain types of changes such as a move or delete operation are not synchronized with a server version of the shared collection. In fact, some other technologies are well known to copy content items that are dragged from one directory to another directory in a shared collection, and especially when ostensibly moving a content item outside of the shared collection. User experiences with such technology exacerbate unintentional deletions and moves in technologies where such safeguards are not desirable or do not exist. 
     Solving this problem is even more difficult when user accounts do not enable kernel (or shell) level extensions that can allow an application managing a shared collection on a client device to be privy to detailed information regarding file moves, deletions, and modifications. Some user accounts do not desire kernel or shell level extensions because, for example, they may add vulnerabilities to the operating system of their computing device. 
     The present technology attempts to solve the above problems without resorting to any kernel (or shell) level modifications, and while still providing natural interactions with the file system (such as permitting moves, deletions, etc.) on the client device, by recognizing potentially unintentional actions and notifying a user. 
     In some embodiments the disclosed technology is deployed in the context of a content management system having content item synchronization capabilities and collaboration features, among others. An example system configuration  100  is shown in  FIG.  1   , which depicts content management system  110  interacting with client device  150 . 
     Accounts 
     Content management system  110  can store content items in association with accounts, as well as perform a variety of content item management tasks, such as retrieve, modify, browse, and/or share the content item(s). Furthermore, content management system  110  can enable an account to access content item(s) from multiple client devices. 
     Content management system  110  supports a plurality of accounts. An entity (user, group of users, company, etc.) can create an account with content management system, and account details can be stored in account database  140 . Account database  140  can store profile information for registered entities. In some cases, profile information for registered entities includes a username and/or email address. Account database  140  can include account management information, such as account type (e.g. various tiers of free or paid accounts), storage space allocated, storage space used, client devices  150  having a registered content management client application  152  resident thereon, security settings, personal configuration settings, etc. 
     Account database  140  can store groups of accounts associated with an entity. Groups can have permissions based on group policies and/or access control lists, and members of the groups can inherit the permissions. For example, a marketing group can have access to one set of content items while an engineering group can have access to another set of content items. An administrator group can modify groups, modify user accounts, etc. 
     Content Item Storage 
     A feature of content management system  110  is the storage of content items, which can be stored in content storage  142 . Content items can be any digital data such as documents, collaboration content items, text files, audio files, image files, video files, webpages, executable files, binary files, etc. A content item can also include collections or other mechanisms for grouping content items together with different behaviors, such as folders, zip files, playlists, albums, etc. A collection can refer to two or more content items stored in folder, or a plurality of content items that are related or grouped by a common attribute. In some embodiments, content storage  142  is combined with other types of storage or databases to handle specific functions. Content storage  142  can store content items, while metadata regarding the content items can be stored in metadata database  146 . Likewise, data regarding where a content item is stored in content storage  142  can be stored in content directory  144 . Additionally, data regarding changes, access, etc. can be stored in server file journal  148 . Each of the various storages/databases such as content storage  142 , content directory  144 , server file journal  148 , and metadata database  146  can be comprised of more than one such storage or database and can be distributed over many devices and locations. Other configurations are also possible. For example, data from content storage  142 , content directory  144 , server file journal  148 , and/or metadata database  146  may be combined into one or more content storages or databases or further segmented into additional content storages or databases. Thus, content management system  110  may include more or less storages and/or databases than shown in  FIG.  1   . 
     In some embodiments, content storage  142  is associated with at least one content management service  116 , which includes software or other processor executable instructions for managing the storage of content items including, but not limited to, receiving content items for storage, preparing content items for storage, selecting a storage location for the content item, retrieving content items from storage, etc. In some embodiments, content management service  116  can divide a content item into smaller chunks for storage at content storage  142 . The location of each chunk making up a content item can be recorded in content directory  144 . Content directory  144  can include a content entry for each content item stored in content storage  142 . The content entry can be associated with a unique ID, which identifies a content item. 
     In some embodiments, the unique ID, which identifies a content item in content directory  144 , can be derived from a deterministic hash function. This method of deriving a unique ID for a content item can ensure that content item duplicates are recognized as such since the deterministic hash function will output the same identifier for every copy of the same content item, but will output a different identifier for a different content item. Using this methodology, content management service  116  can output a unique ID for each content item. 
     Content management service  116  can also designate or record a content path for a content item. The content path can include the name of the content item and/or folder hierarchy associated with the content item. For example, the content path can include a folder or path of folders in which the content item is stored in a local file system on a client device. Content management service  116  can use the content path to present the content items in the appropriate folder hierarchy, such as a tree-like directory structure. While content items are stored in content storage  142  in blocks and may not be stored under a tree like directory structure, such directory structure is a comfortable navigation structure for users Content management service  116  can define or record a content path for a content item wherein the “root” node of a directory structure can be a namespace for each account. Within the namespace can be a directory structure defined by a user of an account and/or content management service  116 . Content directory  144  can store the content path for each content item as part of a content entry. 
     In some embodiments the namespace can include additional namespaces that appear in the directory structure as if they are stored within the root node. This can occur when an account has access to a shared collection. Shared collections can be assigned their own namespace within content management system  110 . While shared collections are actually a root node for the shared collection, they are located subordinate to the user account namespace in the directory structure, and can appear as a folder within a folder for the user account. As addressed above, the directory structure is merely a comfortable navigation structure for users, but does not correlate to storage locations of content items in content storage  142 . 
     While the directory structure in which an account views content items does not correlate to storage locations at content management system  110 , the directory structure can correlate to storage locations on client device  150  depending on the file system used by client device  150 . 
     As addressed above, a content entry in content directory  144  can also include the location of each chunk making up a content item. More specifically, the content entry can include content pointers that identify the location in content storage  142  of the chunks that make up the content item. 
     In addition to a content path and content pointer, a content entry in content directory  144  can also include a user account identifier that identifies the user account that has access to the content item and/or a group identifier that identifies a group with access to the content item. In some embodiments, multiple user account identifiers can be associated with a single content entry indicating that the content item has shared access by the multiple user accounts. In some embodiments, user account identifiers associated with a single content entry can specify different permissions for the associated content item. In some embodiments, content directory  144  can describe a hierarchical structure of content items associated with a user account, the hierarchical structure being specific to the user account. 
     Content management service  116  can decrease the amount of storage space required by identifying duplicate content items or duplicate blocks that make up a content item or versions of a content item. Instead of storing multiple copies, content storage  142  can store a single copy of the content item or block of the content item and content directory  144  can include a pointer or other mechanism to link the duplicates to the single copy. 
     Content management service  116  can also store metadata describing content items, content item types, folders, file path, and/or the relationship of content items to various accounts, collections, or groups in metadata database  146 , in association with the unique ID of the content item. 
     Content management service  116  can also store a log of data regarding changes, access, etc. in server file journal  148 . Server file journal  148  can include the unique ID of the content item and a description of the change or access action along with a time stamp or version number and any other relevant data. Server file journal  148  can also include pointers to blocks affected by the change or content item access. Content management service can provide the ability to undo operations, by using a content item version control that tracks changes to content items, different versions of content items (including diverging version trees), and a change history that can be acquired from the server file journal  148 . The change history can include a set of changes that, when applied to the original content item version, produce the changed content item version. 
     Content Item Synchronization 
     Another feature of content management system  110  is synchronization of content items with at least one client device  150 . Client device(s) can take different forms and have different capabilities. For example, client device  170  is a computing device having a local file system accessible by multiple applications resident thereon. Client device  172  is a computing device wherein content items are only accessible to a specific application or by permission given by the specific application, and the content items are stored either in an application specific space or in the cloud. Client device  174  is any client device accessing content management system  110  via a web browser and accessing content items via a web interface. While example client devices  170 ,  172 , and  174  are depicted in form factors such as a laptop, mobile device, or web browser, it should be understood that the descriptions thereof are not limited to devices of these example form factors. For example a mobile device such as client  172  might have a local file system accessible by multiple applications resident thereon, or client  172  might access content management system  110  via a web browser. As such, the form factor should not be considered limiting when considering client  150 &#39;s capabilities. One or more functions described herein with respect to client device  150  may or may not be available on every client device depending on the specific capabilities of the device—the file access model being one such capability. 
     In many embodiments, client devices are associated with an account of content management system  110 , but in some embodiments client devices can access content using shared links and do not require an account. 
     As noted above, some client devices can access content management system  110  using a web browser. However, client devices can also access content management system  110  using client application  152  stored and running on client device  150 . Client application  152  can include a content item synchronization service  156 . 
     Content item synchronization service  156  can be in communication with content management service  116  to synchronize changes to content items between client device  150  and content management system  110 . 
     Client device  150  can synchronize content with content management system  110  via content synchronization service  156 . The synchronization can be platform agnostic. That is, content can be synchronized across multiple client devices of varying types, capabilities, operating systems, etc. Content synchronization service  156  can synchronize any changes (new, deleted, modified, copied, or moved content items) to content items in a designated location of a file system of client device  150 . 
     Content items can be synchronized from client device  150  to content management system  110 , and vice versa. In embodiments wherein synchronization is from client device  150  to content management system  110 , a user can manipulate content items directly from the file system of client device  150 . Content item synchronization service  156  can watch the file system of the client device to detect changes to content items (write, delete, modify, etc.), and can synchronize the changes to content management system service  120 . In some embodiments, content item synchronization service  156  can perform some functions of content management system service  116  including functions addressed above such as dividing the content item into blocks, hashing the content item to generate a unique identifier, etc. Content synchronization service  156  can index content within client storage index  164  and save the result in storage index  164 . Indexing can include creating a unique identifier for each content item. In some embodiments, content synchronization service  156  creates this unique identifier by putting the data of the content item (e.g., excluding the filename and/or other metadata) through a hash function; as addressed above, content management system can use a similar process to provide identifiers to content on content management system  110 . Content synchronization service  156  can use storage index  164  to facilitate the synchronization of at least a portion of the content within client storage with content associated with a user account on content management system  110 . For example, content synchronization service  156  can compare storage index  164  with content management system  110  and detect differences between content on client storage and content associated with a user account on content management system  110 . Content synchronization service  156  can then attempt to reconcile differences by uploading, downloading, modifying, and deleting content on client storage as appropriate. Content management service  116  can store the changed or new block for the content item and update server file journal  148 , metadata database  146 , content directory  144 , content storage  142 , account database  140 , etc. as appropriate. 
     When synchronizing from content management system  110  to client device  150 , a modification, addition, deletion, move of a content item recorded in server file journal  148  can trigger a notification to be sent to client device  150  using notification service  117 . When client device  150  is informed of the change to server file journal  148 , client device can check storage index  164  to determine if the time stamp of the change occurred since the last synchronization, or determine if the specific change has been synchronized. When client device  150  determines that it is out of synchronization with content management system  110 , content item synchronization service  156  requests content item blocks including the changes, and updates its local copy of the changed content items. In some embodiments, notification service can query other services or databases of content management system  110  such as server file journal  148  to gain more context for the notification, to determine if a notification can be batched with another notification or to supplement a notification. 
     In some embodiments storage index  164  can store some overlapping information as that stored at server file journal  148  as well as some additional information relevant to client device  150 . Storage index  164  can include the unique IDs for each content item, a file path for the content item, a log of each change or update with respect to each content item, a timestamp for the change, etc. Addiitonally storage index can also store a machine ID for each content item stored at client device  150 , and an iNode number. The machine ID is a unique identifier for each content item stored on a specific client device, and an iNode number is a reference number that corresponds to an reference number for the content item in an index or datastructure managed by a file system of client device  150  that includes metadata regarding the content item, including, its storage location in the file system on the client device. 
     Sometimes client device  150  might not have a network connection available. In this scenario, content item synchronization service  156  can monitor the linked collection for content item changes and queue those changes for later synchronization to content management system  110  when a network connection is available. Similarly, a user can manually start, stop, pause, or resume synchronization with content management system  110 . 
     Content item synchronization service  156  can synchronize all content associated with a particular user account on content management system  110 . Alternatively, content item synchronization service  156  can selectively synchronize a portion of the content of the total content associated with the particular user account on content management system  110 . Selectively synchronizing only a portion of the content can preserve space on client device  150  and save bandwidth. 
     In some embodiments, content item synchronization service  156  selectively stores a portion of the content associated with the particular user account and stores placeholder content items in client storage for the remainder portion of the content. For example, content item synchronization service  156  can store a placeholder content item that has the same filename, path, extension, metadata, of its respective complete content item on content management system  110 , but lacking the data of the complete content item. The placeholder content item can be a few kilobytes or less in size while the respective complete content item might be significantly larger. After client device  150  attempts to access the content item, content item synchronization service  156  can retrieve the data of the content item from content management system  110  and provide the complete content item to accessing client device  150 . This approach can provide significant space and bandwidth savings while still providing full access to a user&#39;s content on content management system  110 . 
     Collaboration Features 
     Another feature of content management system  110  is to facilitate collaboration between users. Collaboration features include content item sharing, commenting on content items, co-working on content items, instant messaging, providing presence and seen state information regarding content items, etc. 
     Sharing 
     Content management system  110  can manage sharing content via sharing service  128 . Sharing content by providing a link to the content can include making the content item accessible from any computing device in network communication with content management system  110 . However, in some embodiments a link can be associated with access restrictions enforced by content management system  110 . Sharing content can also include linking content using sharing service  128  to share content within content management system  110  with at least one additional user account (in addition to the original user account associated with the content item) so that each user account has access to the content item. The additional user account can gain access to the content by accepting the content, which will then be accessible through either web interface service  124  or directly from within the directory structure associated with their account on client device  150 . The sharing can be performed in a platform agnostic manner. That is, the content can be shared across multiple client devices  150  of varying type, capabilities, operating systems, etc. The content can also be shared across varying types of user accounts. 
     To share a content item within content management system  110  sharing service  128  can add a user account identifier to a content entry in access control list database  145  associated with the content item, thus granting the added user account access to the content item. Sharing service  128  can also remove user account identifiers from a content entry to restrict a user account&#39;s access to the content item. Sharing service  128  can record content item identifiers, user account identifiers given access to a content item, and access levels in access control list database  145 . 
     To share content items outside of content management system  110 , sharing service  128  can generate a custom network address, such as a uniform resource locator (URL), which allows any web browser to access the content item or collection in content management system  110  without any authentication. To accomplish this, sharing service  128  can include content identification data in the generated URL, which can later be used to properly identify and return the requested content item. For example, sharing service  128  can include the account identifier and the content path or a content item identifying code in the generated URL. Upon selection of the URL, the content identification data included in the URL can be transmitted to content management system  110 , which can use the received content identification data to identify the appropriate content item and return the content item. 
     In addition to generating the URL, sharing service  128  can also be configured to record in access control list database  145  that a URL to the content item has been created. In some embodiments, the content entry associated with a content item can include a URL flag indicating whether a URL to the content item has been created. For example, the URL flag can be a Boolean value initially set to 0 or false to indicate that a URL to the content item has not been created. Sharing service  128  can change the value of the flag to 1 or true after generating a URL to the content item. 
     In some embodiments, sharing service  128  can associate a set of permissions to a URL for a content item. For example, if a user attempts to access the content item via the URL, sharing service  128  can provide a limited set of permissions for the content item. Examples of limited permissions include restrictions that the user cannot download the content item, save the content item, copy the content item, modify the content item, etc. In some embodiments, limited permissions include restrictions that only permit a content item to be accessed from with a specified domain, i.e., from within a corporate network domain, or by accounts associated with a specified domain, e.g., accounts associated with a company account (e.g., @acme.com). 
     In some embodiments, sharing service  128  can also be configured to deactivate a generated URL. For example, each content entry can also include a URL active flag indicating whether the content should be returned in response to a request from the generated URL. For example, sharing service  128  can only return a content item requested by a generated link if the URL active flag is set to 1 or true. Thus, access to a content item for which a URL has been generated can be easily restricted by changing the value of the URL active flag. This allows a user to restrict access to the shared content item without having to move the content item or delete the generated URL. Likewise, sharing service  128  can reactivate the URL by again changing the value of the URL active flag to 1 or true. A user can thus easily restore access to the content item without the need to generate a new URL. 
     In some embodiments, content management system  110  can designate a URL for uploading a content item. For example, a first user with a user account can request such a URL, provide the URL to a contributing user and the contributing user can upload a content item to the first user&#39;s user account using the URL. 
     Presence and Seen State 
     In some embodiments, content management system can provide information about how users with which a content item is shared are interacting or have interacted with the content item. In some embodiments, content management system  110  can report that a user with which a content item is shared is currently viewing the content item. For example, client collaboration service  160  can notify notifications service  117  when client device  150  is accessing the content item. Notifications service  117  can then notify all client devices of other users having access to the same content item of the presence of the user of client device  150  with respect to the content item. 
     In some embodiments, content management system  110  can report a history of user interaction with a shared content item. Collaboration service  126  can query data sources such as metadata database  146  and server file journal  148  to determine that a user has saved the content item, that a user has yet to view the content item, etc., and disseminate this status information using notification service  117  to other users so that they can know who currently is or has viewed or modified the content item. 
     Collaboration service  126  can facilitate comments associated with content, even if a content item does not natively support commenting functionality. Such comments can be stored in metadata database  146 . 
     Collaboration service  126  can originate and transmit notifications for users. For example, a user can mention another user in a comment and collaboration service  126  can send a notification to that user that he has been mentioned in the comment. Various other content item events can trigger notifications, including deleting a content item, sharing a content item, etc. 
     Collaboration service  126  can provide a messaging platform whereby users can send and receive instant messages, voice calls, emails, etc. 
     Collaboration Content Items 
     Collaboration service  126  can also provide an interactive content item collaboration platform whereby users can simultaneously create collaboration content items, comment in the collaboration content items, and manage tasks within the collaboration content items. Collaboration content items can be files that users can create and edit using a collaboration content item editor, and can contain collaboration content item elements. Collaboration content item elements may include a collaboration content item identifier, one or more author identifiers, collaboration content item text, collaboration content item attributes, interaction information, comments, sharing users, etc. Collaboration content item elements can be stored as database entities, which allows for searching and retrieving the collaboration content items. Multiple users may access, view, edit, and collaborate on collaboration content items at the same time or at different times. In some embodiments this can be managed by requiring two users access a content item through a web interface and there they can work on the same copy of the content item at the same time. 
     Collaboration Companion Interface. 
     In some embodiments client collaboration service  160  can provide a native application companion interface for the purpose of displaying information relevant to a content item being presented on client device  150 . In embodiments wherein a content item is accessed by a native application stored and executed on client device  150 , where the content item is in a designated location of the file system of client device  150  such that the content item is managed by content application  152 , the native application may not provide any native way to display the above addressed collaboration data. In such embodiments, client collaboration service  160  can detect that a user has opened a content item, and can provide an overlay with additional information for the content item, such as collaboration data. For example, the additional information can include comments for the content item, status of the content item, activity of other users previously or currently viewing the content item. Such an overlay can warn a user that changes might be lost because another user is currently editing the content item. 
     In some embodiments, one or more of the services or storages/databases discussed above can be accessed using public or private application programming interfaces. 
     Certain software applications can access content storage  142  via an API on behalf of a user. For example, a software package such as an application running on client device  150 , can programmatically make API calls directly to content management system  110  when a user provides authentication credentials, to read, write, create, delete, share, or otherwise manipulate content. 
     A user can view or manipulate content stored in a user account via a web interface generated and served by web interface service  124 . For example, the user can navigate in a web browser to a web address provided by content management system  110 . Changes or updates to content in the content storage  142  made through the web interface, such as uploading a new version of a content item, can be propagated back to other client devices associated with the user&#39;s account. For example, multiple client devices, each with their own client software, can be associated with a single account and content items in the account can be synchronized between each of the multiple client devices. 
     Client device  150  can connect to content management system  110  on behalf of a user. A user can directly interact with client device  150 , for example when client device  150  is a desktop or laptop computer, phone, television, internet-of-things device, etc. Alternatively or additionally, client device  150  can act on behalf of the user without the user having physical access to client device  150 , for example when client device  150  is a server. 
     Some features of client device  150  are enabled by an application installed on client device  150 . In some embodiments, the application can include a content management system specific component. For example, the content management system specific component can be a stand-alone application  152 , one or more application plug-ins, and/or a browser extension. However, the user can also interact with content management system  110  via a third-party application, such as a web browser, that resides on client device  150  and is configured to communicate with content management system  110 . In various implementations, the client-side application  152  can present a user interface (UI) for a user to interact with content management system  110 . For example, the user can interact with the content management system  110  via file system extension  153  integrated with the file system or via a webpage displayed using a web browser application. 
     In some embodiments, client application  152  can be configured to manage and synchronize content for more than one account of content management system  110 . In such embodiments client application  152  can remain logged into multiple accounts and provide normal services for the multiple accounts. In some embodiments, each account can appear as folder in a file system, and all content items within that folder can be synchronized with content management system  110 . In some embodiments, client application  152  can include a selector to choose one of the multiple accounts to be the primary account or default account. 
     While content management system  110  and client device  150  are presented with specific components, it should be understood by one skilled in the art, that the architectural configuration of system  100  is simply one possible configuration and that other configurations with more or fewer components are possible. Further, a service can have more or less functionality, even including functionality described as being with another service. Moreover, features described herein with respect to an embodiment can be combined with features described with respect to another embodiment. 
     File System Warnings 
     As addressed above, the present technology provides a solution to the problem of inadvertent file moves and deletions of content items in a shared collection taking place on client device  150 . 
       FIG.  2    shows an example method for determining that a likely inadvertent content item change has taken place on client device  150 , and notifying a user account of the potential inadvertent content item change. Unless otherwise noted herein, the entire method shown in  FIG.  2    is performed on client device  150  entirely in user application level of the software architecture, i.e., the method shown in  FIG.  2    does not require any modification of or extension into an operating system kernel or shell. The kernel or shell layer handles events from the application layer, such as managing file system events, I/O events with the physical storage, while the application layer is for executing application instructions for applicaitons that interface with the operator/user of client device  150 , or applications that provide services to other applications in the application layer, but do not provide core operating system functions. 
     As shown in  FIG.  2   , content item synchronization service  156  can detect  202  at least one shared content item change event on a client device  150 . In some embodiments the content item synchronization service  156  detects the content item change event by detecting that an unidentified content item is present in a shared collection and detecting the file system path corresponding to the unidentified content item, or by detecting that a previously identified content item is missing from a shared collection and detecting the file system path corresponding to the missing content item. 
     After determining that a content item change has been detected, the method shown in  FIG.  2    attempts to determine what user action caused the content item change to be detected, and then evaluates whether this user action was likely (un)intentional  220 . However, because content item synchronization service  156  is located in application space on client device  150 , content item synchronization service  156  receives limited information regarding the content item change. This limited information is not enough to make the determination of whether the move was likely (un)intentional  220  so content item synchronization service  156  performs several steps to understand the data it does have, and acquire additional data. 
     For example, when the content item change is a folder move and the folder has additional content items stored therein, content item synchronization service  156  can detect a number of content item changes. Content item synchronization service  156  can detect content item changes such as: a folder content item deletion; a folder content item addition; deletions of each of the content items stored within a folder; and additions of each of the content items stored within a folder. Each content item addition and deletion will be detected as a content item change, but content item synchronization service  156  does not know if the content item change reflects a move of a content item, and if the content item change is a move, content item synchronization service  156  needs to determine if the file system path associated with the content item change is a source or a destination, and where the content item is going or has come from. 
     As such, after content item synchronization service  156  detects  202  that a content item has changed, content item synchronization service  156  determines  204  whether the detected change reflects a source or destination of the content item. 
     In some embodiments, content item synchronization service  156  can determine  204  whether the detected change reflects a source or destination of the content item based on whether the content item change is a write or a delete. If the change was to add or write a content item to a directory, then the file system path detected at step  202  is a destination file path. If the change is to remove or delete a content item to a directory, the file system path detected at step  202  is a source file path. 
     In some embodiments content item synchronization service  156  can determine  204  whether the change reflects a source or destination of the content item by checking whether the content item is present at the path. If the content item is present, then it is the destination for the content item change because the file is there. If the content item is not present, then it is the source for the content item change because the file is not there. 
     When content item synchronization service  156  determines  204  that the content item change and associated file system path is for the source of the content item, content item synchronization service  156  can determine  205  whether the content item is located at the source path. In embodiments where determining that a content item is not present at a path is part of the decision making process for step  204 , step  205  can be redundant. However, in embodiments wherein step  204  determines the content item change reflects a source independently of whether the content item is present at the content item path, step  205  can be usefult in determining that the content item change has been reversed already and does not need to be processed, as will be addressed further below. 
     Content item synchronization service  156  can next lookup  206  the file system path in storage index  164  to learn a unique identifier for the content item. Then content item synchronization service  156  can query the file system of operating system on client  150  for the current location (i.e., the destination) of the content item having the unique identifier. In some embodiments content item synchronization service  156  may also look up an inode (data that describes a content item in an index of the operating system) in storage index  164  and query the operating system using the inode information for the content item. The operating system of client device  150  can then return the destination file path for the content item so that content item synchronization service  156  now has both the source path and the destination path for the content item change. 
     When the content item change is determined  204  to refer to a destination of the content item, content item synchronization service  156  can determine whether the content item is currently located at the destination  207 . In some embodiments, as addressed below, such a determination can be useful to determine that the content item change has been reversed already and no longer needs to be processed, and the method can end  209 . 
     Assuming the content item is determined  207  to be present at the destination file path, content item synchronization service  156  can determine  210  the unique identifier directly from the content item, and use the unique identifier to search  212  storage index  164  for the last known file system path for this content item. 
     In some embodiments a source path is not returned  214  by search  212 , then the method can proceed to synchronize the content item change  226  with content management system  110  since the content item change is not a move or a delete, but rather an addition of an unknown (and possibly new file). 
     When the source path is returned  214  by search  212 , content item synchronization service  156  now has both the source path and the destination path for the content item change. 
     Content item synchronization service  156  next determines  216  if the source file system path equals the destination file system path. When content item synchronization service  156  determines  216  that the file system paths are the same, this is likely because the content item change was a content item update or modification, which can likely be safely synchronized  226 . When content item synchronization service  156  determines  216  that the file system paths are not the same, then the content item change is likely a move, and may be unintentional. 
     As addressed above, a single move of a folder can result in several content item changes being reported. In some embodiments the present technology is synchronous and only processes one content item change at a time. In such embodiments, it is desirable to determine the single folder moved and evaluate this action as opposed to evaluating each content item change at the content item level. This can be achieved by determining for any content item change reported to content item synchronization service  156  a highest level unique path between the destination path and the source path, and comparing the highest level unique source path and the highest level unique destination path to identify  218  a highest level canonical move. 
       FIG.  3    conceptually shows the function of step  218 .  FIG.  3    shows a source file system path  302  and a destination file system path  304 . Each path identifies a location at which content item  306  “file.pdf” can be located (or was once located in the case of the source). For both source  302  and destination  304  the content item “file.pdf” is stored in a content item B  308 , which is a folder in the file system of client device  150 . For source  302  content item B  308  was stored in content item A  310 , another folder, but is now stored in content item F  312  for destination  304 . 
     For this set of file system paths, the highest order unique paths are represented in the dashed boxes. For the source, the highest order unique path  314  is “/User/Dropbox/A/” and for the destination, the highest order unique path  316  is “/User/Dropbox/F/.” This indicates that the user moved content item B  308  from content item A  310  to content item F  312 , and any content items such as file.pdf  306  were moved along with content item B  308  since they are dependent on content item B. This move can be termed a canonical move since it is the only unique move that covers all other moves. Should this move likely be unintentional  220 , the easiest way to fix the move is to move content item B  308  back to content item A  310 . 
     One way to determine the canonical move is to evaluate source file system path  302  at each level, starting from the lowest level, at “file.pdf”  306  and determine if this content item is in the correct location. Since “file.pdf” is in directory “F/B” it is not where it is expected to be. The method then iterates up the source path to content item B  308 , which is not where it is expected to be; content item B  308  should be in directory A  310 , not directory F  312 . The method then iterates to content item A  310 , which is in the expected directory “Dropbox.” Once the method finds a content item in the correct location, the method can determine that the canonical move was performed on the previously examined content item—in this case content item B  308 . 
     Once the canonical move is identified, content item synchronization service  156  can determine whether the move was likely unintentional  220 . Using the example shown in  FIG.  3   , content item synchronization service  156  has identified that the canonical move was of content item B  308  from directory A  310  to directory F  312 . Content item synchronization service  156  can utilize at least one heuristic to determine if the move was likely unintentional  220 . One such heuristic can be if content item A  310  is a shared collection, and content item F  312  is not a shared collection, then content item synchronization service  156  can assume that the move was unintentional because moving content item B  308  to a directory that is not shared also causes content item B  308  to not be shared (content item B will inherit the properties of its directory). As such, this move would have taken a shared content item, once synchronized with content management system  110 , and removed it from shared collection A  310  in other users accounts. This is true whether the other users&#39; accounts attempted to access content item B  308  using web interface service  124 , or on their respective client device. 
     When the move is not likely unintentional (i.e., it may be intentional according to the heuristics) the content item change can be synchronized  226  to the content management system. 
     When the move is likely unintentional, content item synchronization service  156  can notify  222  the user using a notification in a graphical user interface displayed on client device  150 . In some embodiments the notification can include a selectable control effective to undo the move or accept the move. If the user confirms the move using the selectable control, the content item change can be synchronized  226  to content management system  110 . If the user acknowledges that the move was unintentional by using the selectable control, the content item change can be undone  224 . 
     Content item synchronization service  156  can queue all content item changes detected  202  for synchronization in a synchronization queue, but with the present technology, content item synchronization service  156  does not synchronize the content item changes in the queue until the conent item change is approved to be synchronized. 
     In some embodiments the move can be undone  224  by replacing the file path associated with the content item that needs to be moved back to its original location with the file system path for its original location. Additionally, content item synchronization service  156  can remove the content item change from the synchronization queue. 
     In some embodiments, prior to moving a content item back to its original location one or more checks can be performed to make sure that the content item should be moved back. Conceptually these checks are designed to make sure everything related to the content item is as content item synchronization service  156  expects it to be and that no subsequent events might call into question the conclusion of heuristics applied at  220 . For example, the unique identifier of the content item to be moved is checked to make sure it matches the unique identifier utilized in steps  208  and  212 . In another example, a time stamp of the content item change is checked to make sure it still reflects the time of change detected at  202 . Once these checks pass, the content item change can be undone  224 . 
     Importantly, the content item change is not synchronized until the method shown in  FIG.  2    is completed so as to not affect other users of the shared content item(s). 
     As addressed above, in some instances a single content item move can result in several related content item changes being reported, but analyzing any one of the related content item moves should be sufficient to render the several related content item changes moot because a determination of one content item move can apply to all of the related content item moves. This scenario can be handled, as addressed above at  207 , wherein, if the content item change reflects a destination, but the content item is not in the destination, this can indicate that the content item change has been undone. Likewise, this scenario can be handled at  205 , if the content item change reflects a source, but the content item is still located at the source, this can indicate that the content item change has been undone. 
     In some embodiments, related content moves can be identified when they refer to the same source file system path. If the content item change was already undone, content item synchronization service  156  can recognize a source that would be subj ect to the same canonical move as identified in  218  and ignore the content item change as having already been handled. 
     In some embodiments, content item synchronization service  156  may learn or detect  202  that the content item change is a move (as opposed to a copy or add) at step  202 . In such embodiments, several determinations such as  205 ,  207 ,  214 , and  216  shown in  FIG.  2    may not be needed since they work, at least in part, to confirm that the content item change is a move or delete action (a delete action can be considerd a move, except that the destination is a recycle bin on client device  150 ). 
     In some embodiments, the method shown in  FIG.  2    is synchronous. In some embodiments, the method shown in  FIG.  2    is at least partially asynchronous. For example, in some embodiments, step  220  wherein heuristics are applied to determine if a move was likely unintentional, can include some rules that might take more time to run than is desired. In such embodiments, content item synchronization service  156  can determine that the determination  220  is taking longer than allowed for a content item move, and continue to process the content item changes. However, content item changes effected by the same canonical move  218  can be batched for processing once the original content item change has completed processing to determine if the move was unintentional  220 . 
     While throughout this description it has been dscribed that content item changes are not undone until it is determined that the content item change is likely unintentional, in some embodiments the change can be immediately undone, and thereafter it can be determined if the move should have been permitted. When the move should have been permitted content item synchronization service  156  can redo the move. Sometimes users may select multiple files/folders to do batch move/deletion. In such embodiments similar kinds of events can be queued to show a single notification for the batched moves/deletions to avoid notifying users multiple times for each action in the batch. In some emobidements, the queueing can be done through a timer to quarantine similar kinds of moves and if there has not been any new events of similar kinds beyond a certain time threshold, the single notification can be displayed. 
       FIG.  4    shows an example of computing system  400  in which the components of the system are in communication with each other using connection  405 . Connection  405  can be a physical connection via a bus, or a direct connection into processor  410 , such as in a chipset architecture. Connection  405  can also be a virtual connection, networked connection, or logical connection. 
     In some embodiments computing system  400  is a distributed system in which the functions described in this disclosure can be distributed within a datacenter, multiple datacenters, a peer network, etc. In some embodiments, one or more of the described system components represents many such components each performing some or all of the function for which the component is described. In some embodiments, the components can be physical or virtual devices. 
     Example system  400  includes at least one processing unit (CPU or processor)  410  and connection  405  that couples various system components including system memory  415 , such as read only memory (ROM) and random access memory (RAM) to processor  410 . Computing system  400  can include a cache of high-speed memory connected directly with, in close proximity to, or integrated as part of processor  410 . 
     Processor  410  can include any general purpose processor and a hardware service or software service, such as services  432 ,  434 , and  436  stored in storage device  430 , configured to control processor  410  as well as a special-purpose processor where software instructions are incorporated into the actual processor design. Processor  410  may essentially be a completely self-contained computing system, containing multiple cores or processors, a bus, memory controller, cache, etc. A multi-core processor may be symmetric or asymmetric. 
     To enable user interaction, computing system  400  includes an input device  445 , which can represent any number of input mechanisms, such as a microphone for speech, a touch-sensitive screen for gesture or graphical input, keyboard, mouse, motion input, speech, etc. Computing system  400  can also include output device  435 , which can be one or more of a number of output mechanisms known to those of skill in the art. In some instances, multimodal systems can enable a user to provide multiple types of input/output to communicate with computing system  400 . Computing system  400  can include communications interface  440 , which can generally govern and manage the user input and system output. There is no restriction on operating on any particular hardware arrangement and therefore the basic features here may easily be substituted for improved hardware or firmware arrangements as they are developed. 
     Storage device  430  can be a non-volatile memory device and can be a hard disk or other types of computer readable media which can store data that are accessible by a computer, such as magnetic cassettes, flash memory cards, solid state memory devices, digital versatile disks, cartridges, random access memories (RAMs), read only memory (ROM), and/or some combination of these devices. 
     The storage device  430  can include software services, servers, services, etc., that when the code that defines such software is executed by the processor  410 , it causes the system to perform a function. In some embodiments, a hardware service that performs a particular function can include the software component stored in a computer-readable medium in connection with the necessary hardware components, such as processor  410 , connection  405 , output device  435 , etc., to carry out the function. 
     For clarity of explanation, in some instances the present technology may be presented as including individual functional blocks including functional blocks comprising devices, device components, steps or routines in a method embodied in software, or combinations of hardware and software. 
     Any of the steps, operations, functions, or processes described herein may be performed or implemented by a combination of hardware and software services or services, alone or in combination with other devices. In some embodiments, a service can be software that resides in memory of a client device and/or one or more servers of a content management system and perform one or more functions when a processor executes the software associated with the service. In some embodiments, a service is a program, or a collection of programs that carry out a specific function. In some embodiments, a service can be considered a server. The memory can be a non-transitory computer-readable medium. 
     In some embodiments the computer-readable storage devices, mediums, and memories can include a cable or wireless signal containing a bit stream and the like. However, when mentioned, non-transitory computer-readable storage media expressly exclude media such as energy, carrier signals, electromagnetic waves, and signals per se. 
     Methods according to the above-described examples can be implemented using computer-executable instructions that are stored or otherwise available from computer readable media. Such instructions can comprise, for example, instructions and data which cause or otherwise configure a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. Portions of computer resources used can be accessible over a network. The computer executable instructions may be, for example, binaries, intermediate format instructions such as assembly language, firmware, or source code. Examples of computer-readable media that may be used to store instructions, information used, and/or information created during methods according to described examples include magnetic or optical disks, solid state memory devices, flash memory, USB devices provided with non-volatile memory, networked storage devices, and so on. 
     Devices implementing methods according to these disclosures can comprise hardware, firmware and/or software, and can take any of a variety of form factors. Typical examples of such form factors include servers, laptops, smart phones, small form factor personal computers, personal digital assistants, and so on. Functionality described herein also can be embodied in peripherals or add-in cards. Such functionality can also be implemented on a circuit board among different chips or different processes executing in a single device, by way of further example. 
     The instructions, media for conveying such instructions, computing resources for executing them, and other structures for supporting such computing resources are means for providing the functions described in these disclosures. 
     Although a variety of examples and other information was used to explain aspects within the scope of the appended claims, no limitation of the claims should be implied based on particular features or arrangements in such examples, as one of ordinary skill would be able to use these examples to derive a wide variety of implementations. Further and although some subject matter may have been described in language specific to examples of structural features and/or method steps, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to these described features or acts. For example, such functionality can be distributed differently or performed in components other than those identified herein. Rather, the described features and steps are disclosed as examples of components of systems and methods within the scope of the appended claims.