[−][src]Crate barc

Body Archive container file format, reader and writer.

BARC is a container file format for the storage or one to many HTTP request/response dialog records. A fixed length, ASCII-only record head specifies lengths of a subsequent series of request and response header blocks and bodies which are stored as raw (unencoded) bytes. When not using the internal compression feature, the format is easily human readable. With compression, the barc CLI tool (barc-cli crate) can be used to view records.

See some sample files in source sample/*.barc.

Other features:

An additional meta-headers block provides more recording details and can also be used to store application-specific values.
Sequential or random-access reads by record offset (which could be stored in an external index or database).
Single-writer sessions are guaranteed safe with N concurrent readers (in or out of process).
Optional per-record gzip or Brotli compression (headers and bodies)

Structs

BarcFile	Reference to a BARC File by `Path`, supporting up to 1 writer and N readers concurrently.
BarcReader	BARC file handle for read access. Each reader has its own file handle and position.
BarcWriter	BARC file handle for write access.
BrotliCompressStrategy	Strategy for Brotli compression. Will only compress if a minimum length of compressible bytes, from the response and request bodies and headers is found.
EncodeWrapper	Wrapper holding a potentially encoding `Write` reference for the underlying BARC `File` reference.
GzipCompressStrategy	Strategy for gzip compression. Will only compress if a minimum length of compressible bytes, from the response and request bodies and headers is found.
NoCompressStrategy	Strategy of no (aka `Plain`) compression.
Record	An owned BARC record with public fields.

Enums

BarcError	Error enumeration for all barc module errors. This may be extended in the future, so exhaustive matching is gently discouraged with an unused variant.
Compression	BARC record compression mode.
DialogConvertError	Error enumeration for failures when converting from a `Record` to a `Dialog`.
RecordType	BARC record type.

Constants

V2_HEAD_SIZE	Fixed record head size including CRLF terminator: 54 Bytes
V2_MAX_RECORD	Maximum total record length, excluding the record head: 2⁴⁸ (256 TiB) - 1. Note: this exceeds the file or partition size limits of many file-systems.
V2_MAX_HBLOCK	Maximum header (meta, request, response) block size, including any CRLF terminator: 2²⁰ (1 MiB) - 1.
V2_MAX_REQ_BODY	Maximum request body size, including any CRLF terminator: 2⁴⁰ (1 TiB) - 1.

Traits

CompressStrategy	Strategies for BARC record compression encoding on write.
MetaRecorded	Access to BARC `Record` compatible objects by reference, extending `Recorded` with meta-headers and a record type.

Functions

hname_meta_method	Meta `HeaderName` for the HTTP method used in the request, e.g. "GET", "POST", etc.
hname_meta_res_decoded	Meta `HeaderName` for a list of content or transfer encodings decoded for the current response body. The value is in HTTP content-encoding header format, e.g. "chunked, gzip".
hname_meta_res_status	Meta `HeaderName` for the response numeric status code, SPACE, and then a standardized reason phrase, e.g. "200 OK". The later is intended only for human readers.
hname_meta_res_version	Meta `HeaderName` for the response version, e.g. "HTTP/1.1", "HTTP/2.0", etc.
hname_meta_url	Meta `HeaderName` for the complete URL used in the request.
write_body	Write body to out, with optional CR+LF end padding, and return the length written. This is primarily an implementation detail of `BarcWriter`, but is made public for its general diagnostic utility.
write_headers	Write header block to out, with optional CR+LF end padding, and return the length written. This is primarily an implementation detail of `BarcWriter`, but is made public for its general diagnostic utility.

Type Definitions

Flaw	Conveniently compact type alias for dyn Trait `std::error::Error`. It is possible to query and downcast the type via methods of `std::any::Any`.