Node: Disk format, Previous: Purging, Up: Disk cache



Format of the on-disk cache

The on-disk cache consists of a collection of files, one per instance. The format of an on-disk resource is similar to that of an HTTP message: it starts with an HTTP status line, followed by HTTP headers, followed by a blank line (\r\n\r\n). The blank line is optionally followed by a number of binary zeroes. The body of the instance follows.

The headers of an on-disk file have a few minor differences with HTTP messages. Obviously, there is never a Transfer-Encoding line. A few additional headers are used by Polipo for its internal bookkeeping: