# colfer **Repository Path**: leopku/colfer ## Basic Information - **Project Name**: colfer - **Description**: No description available - **Primary Language**: Unknown - **License**: CC0-1.0 - **Default Branch**: master - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 0 - **Forks**: 0 - **Created**: 2020-09-21 - **Last Updated**: 2024-06-09 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README # Colfer [![Build Status](https://travis-ci.org/pascaldekloe/colfer.svg?branch=master)](https://travis-ci.org/pascaldekloe/colfer) Colfer is a binary serialization [format](https://github.com/pascaldekloe/colfer/wiki/Spec) optimized for speed and size. The project's compiler `colf(1)` generates source code from schema definitions to marshal and unmarshall data structures. This is free and unencumbered software released into the [public domain](http://creativecommons.org/publicdomain/zero/1.0). The format is inspired by Proto**col** Buf**fer**s. #### Language Support * C, ISO/IEC 9899:2011 compliant a.k.a. C11, C++ compatible * Go, a.k.a. golang * Java, Android compatible * JavaScript, a.k.a. ECMAScript, NodeJS compatible #### Features * Simple and straightforward in use * No dependencies other than the core library * Both faster and smaller than the competition * [Robust](#security) against malicious input * Maximum of 127 fields per data structure * No support for enumerations * Framed; suitable for concatenation/streaming #### TODO's * Rust and Python support * Protocol [revision](https://github.com/pascaldekloe/colfer/commits/v2) ## Use Download a [prebuilt compiler](https://github.com/pascaldekloe/colfer/releases) or run `go get -u github.com/pascaldekloe/colfer/cmd/colf` to make one yourself. Homebrew users can also `brew install colfer`. The command prints its own manual when invoked without arguments. ``` NAME colf — compile Colfer schemas SYNOPSIS colf [-h] colf [-vf] [-b directory] [-p package] \ [-s expression] [-l expression] C [file ...] colf [-vf] [-b directory] [-p package] [-t files] \ [-s expression] [-l expression] Go [file ...] colf [-vf] [-b directory] [-p package] [-t files] \ [-x class] [-i interfaces] [-c file] \ [-s expression] [-l expression] Java [file ...] colf [-vf] [-b directory] [-p package] \ [-s expression] [-l expression] JavaScript [file ...] DESCRIPTION The output is source code for either C, Go, Java or JavaScript. For each operand that names a file of a type other than directory, colf reads the content as schema input. For each named directory, colf reads all files with a .colf extension within that directory. If no operands are given, the contents of the current directory are used. A package definition may be spread over several schema files. The directory hierarchy of the input is not relevant to the generated code. OPTIONS -b directory Use a base directory for the generated code. (default ".") -c file Insert a code snippet from a file. -f Normalize the format of all schema input on the fly. -h Prints the manual to standard error. -i interfaces Make all generated classes implement one or more interfaces. Use commas as a list separator. -l expression Set the default upper limit for the number of elements in a list. The expression is applied to the target language under the name ColferListMax. (default "64 * 1024") -p package Compile to a package prefix. -s expression Set the default upper limit for serial byte sizes. The expression is applied to the target language under the name ColferSizeMax. (default "16 * 1024 * 1024") -t files Supply custom tags with one or more files. Use commas as a list separator. See the TAGS section for details. -v Enable verbose reporting to standard error. -x class Make all generated classes extend a super class. TAGS Tags, a.k.a. annotations, are source code additions for structs and/or fields. Input for the compiler can be specified with the -f option. The data format is line-oriented. :≡ ; :≡ '.' ; :≡ | '.' ; Lines starting with a '#' are ignored (as comments). Java output can take multiple tag lines for the same struct or field. Each code line is applied in order of appearance. EXIT STATUS The command exits 0 on success, 1 on error and 2 when invoked without arguments. EXAMPLES Compile ./io.colf with compact limits as C: colf -b src -s 2048 -l 96 C io.colf Compile ./*.colf with a common parent as Java: colf -p com.example.model -x com.example.io.IOBean Java BUGS Report bugs at . Text validation is not part of the marshalling and unmarshalling process. C and Go just pass any malformed UTF-8 characters. Java and JavaScript replace unmappable content with the '?' character (ASCII 63). SEE ALSO protoc(1), flatc(1) ``` It is recommended to commit the generated source code into the respective version control to preserve build consistency and minimise the need for compiler installations. Alternatively, you may use the [Maven plugin](https://github.com/pascaldekloe/colfer/wiki/Java#maven). ```xml net.quies.colfer colfer-maven-plugin 1.11.2 com/example ``` ## Schema Data structures are defined in `.colf` files. The format is quite self-explanatory. ``` // Package demo offers a demonstration. // These comment lines will end up in the generated code. package demo // Course is the grounds where the game of golf is played. type course struct { ID uint64 name text holes []hole image binary tags []text } type hole struct { // Lat is the latitude of the cup. lat float64 // Lon is the longitude of the cup. lon float64 // Par is the difficulty index. par uint8 // Water marks the presence of water. water bool // Sand marks the presence of sand. sand bool } ``` See what the generated code looks like in [C](https://gist.github.com/pascaldekloe/05e903f12a4f02a995f71d0c18872b65), [Go](https://gist.github.com/pascaldekloe/786fd46e6e4710c14fee7da1f480c2d4), [Java](https://gist.github.com/pascaldekloe/b54326e6b7c5e9f036911a8cbea6ccbf) or [JavaScript](https://gist.github.com/pascaldekloe/5653c8bb074ebd29ffcc0deece7495a4). The following table shows how Colfer data types are applied per language. | Colfer | C | Go | Java | JavaScript | |:--------------|:----------------------|:--------------|:--------------|:--------------| | bool | char | bool | boolean | Boolean | | uint8 | uint8_t | uint8 | byte † | Number | | uint16 | uint16_t | uint16 | short † | Number | | uint32 | uint32_t | uint32 | int † | Number | | uint64 | uint64_t | uint64 | long † | Number ‡ | | int32 | int32_t | int32 | int | Number | | int64 | int64_t | int64 | long | Number ‡ | | float32 | float | float32 | float | Number | | float64 | double | float64 | double | Number | | timestamp | timespec | time.Time †† | time.Instant | Date + Number | | text | const char* + size_t | string | String | String | | binary | uint8_t* + size_t | []byte | byte[] | Uint8Array | | list | * + size_t | slice | array | Array | * † signed representation of unsigned data, i.e. may overflow to negative. * ‡ range limited to [1 - 2⁵³, 2⁵³ - 1] * †† timezone not preserved Lists may contain floating points, text, binaries or data structures. ## Security Colfer is suited for untrusted data sources such as network I/O or bulk streams. Marshalling and unmarshalling comes with built-in size protection to ensure predictable memory consumption. The format prevents memory bombs by design. The marshaller may not produce malformed output, regardless of the data input. In no event may the unmarshaller read outside the boundaries of a serial. Fuzz testing did not reveal any volnurabilities yet. Computing power is welcome. ## Compatibility Name changes do not affect the serialization format. Deprecated fields should be renamed to clearly discourage their use. For backwards compatibility new fields must be added to the end of colfer structs. Thus the number of fields can be seen as the schema version. ## Performance Colfer aims to be the fastest and the smallest format without compromising on reliability. See the [benchmark wiki](https://github.com/pascaldekloe/colfer/wiki/Benchmark) for a comparison. Suboptimal performance is treated like a bug.