Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for file system management. In one aspect, a method includes receiving a request at a kernel to perform a file operation on a particular file; identifying a flag bit associated with the file; invoking user space file handler to perform particular action when the flag bit is set; determining whether notification that action has been performed by file handler is received; and allowing the file operation on the file when notification is received.

Abstract: Systems and methods are provided for storing and restoring digital data. In some implementations, a method is provided. The method includes initiating a backup operation of data including a plurality of items, interrupting the backup operation, where interrupting occurs after a portion of the data has been completed, receiving an input to resume the backup operation, identifying a previously completed portion of the backup data, and performing a backup of a remaining uncompleted portion of the backup data. Other embodiments of this aspect include corresponding systems, apparatus, computer program products, and computer readable media.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for transferring electronic data. In general, one aspect of the subject matter described in this specification can be embodied in methods that include the actions of identifying a data item to be chunked; determining the type of the data item; determining whether the type of the data item is one of a specified one or more types; if it is determined that the type of the data item is not one of the specified one or more types, performing a first chunking of the data item; and if it is determined that the type of the data item is one of the specified one or more types, performing a second chunking of the data item that is based on the particular content portions of the data item.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for data synchronization. In general, one aspect of the subject matter described in this specification can be embodied in methods that include the actions of receiving a knowledge vector from a first device of the pair of devices, the knowledge vector identifying data items and latest changes to the data items known to the peer device; comparing, at a second device of the pair of devices, the received knowledge vector with a local knowledge vector for changes unknown to the first device; and sending a list of changes to the first device.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for data storage. In one aspect, a method includes the actions of identifying a running query from an application; determining one or more data items of a plurality of data items that the application has permission to view according to one or more application specific access policies; and presenting the one or more data items to the application while not presenting other data items of the plurality of data items.

Abstract: Systems and methods are disclosed that track a document within a file system using document identifier (DOCID) that is preserved during safe save operations. The DOCID can be a universally unique identifier (UUID). The DOCID can be generated on a local file system or generated during a synchronization process with a remote synchronization service. Applications can opt in to document tracking. The kernel of the operating system can monitor file system operations on a per-application and per-thread basis and determine when a processing thread is about to perform a safe save. When a sequence of file system operations indicates that a safe save is to be performed, the kernel can generate and store a tombstone record that includes the DOCID and other metadata of the tracked document and pass the DOCID and metadata to the newly saved document.

Abstract: A cloud computing system can be used to transparently reduce the storage space of an application on a client device. An application can be installed with a minimal set of application resource files. The remaining application resource files can be replaced with application resource file placeholders, which can have the appearance of application resource files but are in fact empty files. When an application requests an application resource file, an application resource file retrieval process installed on the client device can detect the difference between an application resource file and an application resource file placeholder. The application resource file retrieval process can trigger a fault in response to detecting an application resource file placeholder, which causes the client device to obtain the requested application resource file from a remote storage location, such as cloud-based storage. Additionally, installed application resource files can be replaced with application resource file placeholders.

Abstract: A cloud computing system can be used to transparently reduce the storage space of an application on a client device. An application can be installed with a minimal set of application resource files. The remaining application resource files can be replaced with application resource file placeholders, which can have the appearance of application resource files but are in fact empty files. When an application requests an application resource file, an application resource file retrieval process installed on the client device can detect the difference between an application resource file and an application resource file placeholder. The application resource file retrieval process can trigger a fault in response to detecting an application resource file placeholder, which causes the client device to obtain the requested application resource file from a remote storage location, such as cloud-based storage. Additionally, installed application resource files can be replaced with application resource file placeholders.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for file system management. In one aspect, a method includes receiving a request at a kernel to perform a file operation on a particular file; identifying a flag bit associated with the file; invoking user space file handler to perform particular action when the flag bit is set; determining whether notification that action has been performed by file handler is received; and allowing the file operation on the file when notification is received.

Abstract: Systems and methods are provided for storing and restoring digital data. In some implementations, a method is provided. The method includes initiating a backup operation of data including a plurality of items, interrupting the backup operation, where interrupting occurs after a portion of the data has been completed, receiving an input to resume the backup operation, identifying a previously completed portion of the backup data, and performing a backup of a remaining uncompleted portion of the backup data. Other embodiments of this aspect include corresponding systems, apparatus, computer program products, and computer readable media.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for data synchronization. In general, one aspect of the subject matter described in this specification can be embodied in methods that include the actions of receiving a knowledge vector from a first device of the pair of devices, the knowledge vector identifying data items and latest changes to the data items known to the peer device; comparing, at a second device of the pair of devices, the received knowledge vector with a local knowledge vector for changes unknown to the first device; and sending a list of changes to the first device.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for transferring electronic data. In general, one aspect of the subject matter described in this specification can be embodied in methods that include the actions of identifying a data item to be chunked; determining the type of the data item; determining whether the type of the data item is one of a specified one or more types; if it is determined that the type of the data item is not one of the specified one or more types, performing a first chunking of the data item; and if it is determined that the type of the data item is one of the specified one or more types, performing a second chunking of the data item that is based on the particular content portions of the data item.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for file system management. In one aspect, a method includes receiving a request at a kernel to perform a file operation on a particular file; identifying a flag bit associated with the file; invoking user space file handler to perform particular action when the flag bit is set; determining whether notification that action has been performed by file handler is received; and allowing the file operation on the file when notification is received.

Abstract: Systems and methods are provided for storing and restoring digital data. In some implementations, a method is provided. The method includes initiating a backup operation of data including a plurality of items, interrupting the backup operation, where interrupting occurs after a portion of the data has been completed, receiving an input to resume the backup operation, identifying a previously completed portion of the backup data, and performing a backup of a remaining uncompleted portion of the backup data. Other embodiments of this aspect include corresponding systems, apparatus, computer program products, and computer readable media.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for storing data. In one aspect, a method includes receiving a user input to present a visual representation of a first prior state of a file system; generating the first visual representation of a first prior state of the file system at a first time in the past according to a first virtual file system corresponding to that first time; presenting the first visual representation, where the first virtual file system is a reduced representation of the file system at that first time; receiving a user input to present a second visual representation of a second prior state of the file system at a second time in the past according to a second virtual file system corresponding to that second time; and presenting the second visual representation.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for transferring electronic data. In general, one aspect of the subject matter described in this specification can be embodied in methods that include the actions of identifying a data item to be chunked; determining the type of the data item; determining whether the type of the data item is one of a specified one or more types; if it is determined that the type of the data item is not one of the specified one or more types, performing a first chunking of the data item; and if it is determined that the type of the data item is one of the specified one or more types, performing a second chunking of the data item that is based on the particular content portions of the data item.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for data synchronization. In general, one aspect of the subject matter described in this specification can be embodied in methods that include the actions of receiving a knowledge vector from a first device of the pair of devices, the knowledge vector identifying data items and latest changes to the data items known to the peer device; comparing, at a second device of the pair of devices, the received knowledge vector with a local knowledge vector for changes unknown to the first device; and sending a list of changes to the first device.

Abstract: Systems, methods and computer program products are disclosed for associating unique identifiers to files of a file system to indicate that the contents of the files have changed. In some implementations, a counter value associated with a file is incremented or decremented each time the file contents are changed. The unique identifier may be stored with the file contents and file metadata in the cache. When a process requests access to the cached file contents, the process requests the unique identifier from a system component and compares the unique identifier with the unique identifier returned by the system component. If the two unique identifiers are the same, the cached file contents are deemed valid and can be used by the process. If the two unique identifiers are different, the cached file contents are deemed invalid.

Abstract: Systems and methods are provided for performing backup operations while a user is using a device. In one implementation, a method is provided. A backup operation of data including a plurality of related items is initiated. Modifications to one or more items of the plurality of related items are monitored for during the backup operation. The backup operation is completed. If a modification occurred to one or more items, a second backup operation is performed for the modified items.

Abstract: A cloud computing system can be used to transparently reduce the storage space of an application on a client device. An application can be installed with a minimal set of application resource files. The remaining application resource files can be replaced with application resource file placeholders, which can have the appearance of application resource files but are in fact empty files. When an application requests an application resource file, an application resource file retrieval process installed on the client device can detect the difference between an application resource file and an application resource file placeholder. The application resource file retrieval process can trigger a fault in response to detecting an application resource file placeholder, which causes the client device to obtain the requested application resource file from a remote storage location, such as cloud-based storage. Additionally, installed application resource files can be replaced with application resource file placeholders.