Metadata structures for mass P2P file sharing

• US 7,558,797 B2
• Filed: 06/30/2006
• Issued: 07/07/2009
• Est. Priority Date: 06/30/2006
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Li, Jin
• Primary Examiner(s): Vo; Tim T.
• Assistant Examiner(s): Gortayo; Dangelino N
• Application Number:
  US11/427,994
• Publication Number:
  US 20080005120A1
• Time in Patent Office: 1,103 Days
• Field of Search: 707/1, 707/3, 707/5, 707/100, 707/104.1, 709/217, 709/204
• US Class Current: 1/1
• CPC Class Codes: G06F 16/14 Details of searching files based on file metadata
• CPC Class Codes: G06F 16/1837 Management specially adapted to peer-to-peer storage networks topology management mechanisms of peer-to-peer networks H04L67/1042
• CPC Class Codes: H04L 67/104 Peer-to-peer [P2P] networks
• CPC Class Codes: H04L 67/108 characterised by resources being split in blocks or fragments
• CPC Class Codes: H04L 67/1091 Interfacing with client-server systems or between P2P systems
• CPC Class Codes: H04L 67/1093 Some peer nodes performing special functions
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing

Abstract

A “Mass File Sharer” (MFS) provides a mass P2P file sharing protocol with optional on-demand file access across a P2P network. Unlike conventional P2P file sharing, the MFS simultaneously asynchronously shares large numbers of files, while providing optional on-demand (synchronous) access to shared files. The MFS uses a unique metadata structure in combination with an inter-peer file/folder version analysis and an inter-peer file/folder availability analysis to share complex directory structures that may include any number of folders, sub-folders, and files. Sharing may be asynchronous and/or synchronous. Specifically, file sharing is generally accomplished as an asynchronous distribution across the network. However, when a particular peer wants direct access particular files, an on-demand access mode is used to enable synchronous delivery of shared files. This combination of asynchronous and synchronous file distribution enables the MFS to support a number of applications, such as on-demand movie viewing, file/folder browsing, etc.

Claims

1. A computer-readable medium having computer executable instructions for providing content definitions for coordinating content sharing in a peer-to-peer (P2P) network, said computer executable instructions comprising:

for each of a plurality of peers, identifying one or more matching peers in a P2P network, said matching peers having corresponding content sharing interests;

for each matching peer and starting at a sharing root of each matching peer, preparing a root metadata ID file describing the content to be shared between the matching peers;

wherein the sharing root of each matching peer represents a directory tree structure of folders and files to be shared by each peer;

wherein each metadata ID includes data that describes the directory tree structure of folders and files comprising the content to be shared by each matching peer;

wherein each metadata ID further includes data defining version chains representing a version history comprising a history of all past versions of the directory tree structure and any folders and files in that directory tree as known by each matching peer including a most recent modification to any of the directory tree structure and to any folders and files in that directory tree comprising the content to be shared by each matching peer; and

exchanging the root metadata ID file prepared for each matching peer with every other matching peer via the P2P network to identify a set of shared files and folders between the matching peers.

2. The computer-readable medium of claim 1 wherein each peer:

establishes a local lookup table to hold an identification of all shared folders and files of the current peer and

after exchanging the root metadata ID with each other peer, performs a table lookup to identify commonly shared folders and files by comparing each received metadata ID with the local lookup table.

3. The computer-readable medium of claim 1 wherein the version chains include timestamps corresponding to the content to be shared for identifying the most recent modifications to any of the directory tree structure and to any folders and files in that directory tree.

4. The computer-readable medium of claim 1 wherein the version chains include hashes of the content to be shared for identifying the most recent modifications to any of the directory tree structure and to any folders and files in that directory tree.

5. The computer-readable medium of claim 1 wherein the version chains include signatures of the content to be shared by each matching peer for identifying the most recent modifications to any of the directory tree structure and to any folders and files in that directory tree.

6. The computer-readable medium of claim 1 further comprising for each matching peer, preparing an availability vector describing which portions of the content to be shared are held by each matching peer, and exchanging that availability vector with every other matching peer via the P2P network.

7. The computer-readable medium of claim 1 further comprising exchanging the version chains between two or more peers, and comparing the exchanged version chains to identify the more current content between those peers.

8. The computer-readable medium of claim 7 wherein:

a portion of the shared files and folders are identified for synchronous access, thereby giving a higher priority to those files and folders during corresponding data transfers of those files and folders via the P2P network; and

wherein the rest of the shared files and folders are identified for asynchronous access, thereby giving a lower priority to those files and folders during corresponding data transfers of those files and folders via the P2P network.

9. A method for identifying data to be shared between peers in a peer-to peer (P2P) network, comprising using a computing device for:

using one or more peer computing devices to query a P2P network to identify one or more matching peer computing devices having matching data sharing interests;

using each of the peer computing devices to locally prepare a root metadata ID for a root of a shared folder corresponding to the matching data sharing interests of each of those peer computing devices;

wherein the root of the shared folder represents a directory tree structure of folders and files to be shared;

wherein each root metadata ID, further includes data representing one or more of a timestamp, a unique signature and a unique hash, and wherein the timestamps, signatures and hashes are created as a function of a most recent modification to the any of the directory tree structure and any folders and files described by the root metadata ID to create a version chain which defines a history of modifications representing a history of all past versions of directory tree structure of folders and files to be shared as known by each peer computing device; and

exchanging the root metadata ID prepared by each peer computing device with every other matching peer computing device via the P2P network.

10. The method of claim 9 further comprising for each peer computing device, locally comparing the root metadata ID received from each other peer computing with the locally prepared root metadata ID to determine a set of files and folders that are commonly shared between the peers.

11. The method of claim 10 further comprising for each peer computing device, locally preparing an availability vector describing which portions of the folders and files are locally held by each peer computing device and exchanging that availability vector with every other matching peer computing device via the P2P network.

12. The method of claim 11 further comprising sharing the folders and files between two or more of the matching peer computing devices via the P2P network after the exchanging of the availability vectors.

13. A system for coordinating content sharing interests between peers in a peer-to-peer (P2P) network, comprising:

for each of a plurality of peers attached to a P2P network, means for identifying one or more matching peers in a P2P network that have corresponding content sharing interests corresponding to a root share folder of each peer;

for the root share folder of each matching peer, means for preparing a metadata ID describing a directory tree structure of folders and files contained within the root share folder as a function of the corresponding content sharing interests;

wherein each metadata ID further includes data defining version chains representing a version history comprising a history of all past versions of the root share folder and any folders and files contained with the root share folder as known by each matching peer including a most recent modification to any of the root share folder and any folders and files contained with the root share folder;

means for exchanging the metadata ID prepared by each peer with every other matching peer via the P2P network; and

for each peer, means for evaluating the received metadata ID'"'"'s to identify commonly shared file and folders.

14. The system of claim 13 further comprising for each peer, means for locally preparing an availability vector describing which portions of the folders and files are locally held by each peer, and exchanging that availability vector with every other matching peer via the P2P network.

15. The system of claim 14 further comprising means for sharing the folders and files between two or more of the matching peers via the P2P network after the exchange of the availability vectors.

16. The system of claim 13 further comprising for each peer, means for establishing a local lookup table to hold identification information of all commonly shared folders and files.