Comprehensive Design Overview | Bureau Query Applet
The Jigsaw Label bureau serves PICS labels from a SQL database via the interfaces defined in the PICS Label Specification and extensions to those interfaces. The label bureau is implemented as a Jigsaw resource in Java, with a JDBC link to a SQL database. It has been tested on the Win32 platform with a Microsoft SQL database.
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The label bureau fully supports the PICS Label Specification for label queries. |
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The label bureau has the capability to accept RAT files (MIME type application/pics-service) and generate SQL tables on the fly to store labels. |
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The label bureau has the capability to accept PICS labels (MIME type application/pics-labels) and store those labels in the database for future retrieval by HTTP GET. |
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The label bureau has the capability to accept PICS Rules (MIME type application/pics-rules) and search for labels matching the PICSRule's criteria. |
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Labels whose RAT files have not been received yet are stored in a binary format in the SQL database. |
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The label bureau supports concurrent access of the database by establishing multiple database connections, and dynamically allocating those connections to threads requesting labels. This preserves the concurrency and high performance of the underlying database, while ensuring safe data access. |
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The label bureau uses W3C-standard Java objects (the PICS Standard Library). |
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(1/16/98) URLs are not parsed yet; this will be implemented after migration to the PICS Standard Library. |
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(11/21/97) When labels are encountered whose RAT files are unknown, the database uses a binary format for storing labels. There may be cross-platform/cross-database issues associated with this strategy. The relevant code has been successfully tested on the Windows NT platform with a Microsoft SQL Server database and the Microsoft JDBC-ODBC bridge. This is anticipated to be the most common implementation. |
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PUT Extension for submission of PICS labels to a label bureau. |
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PICSRules Extension for submission of PICS label searches to a label bureau. |
Last Modified 16 January, 1998, Kyle Jamieson jamieson@mit.edu