Vermay: Version Management Format for Articles withby YAML front-matter Markdown

Official Dart implementation of Vermay, a lightweight binary diff format and versioning system for content files, designed for custom CMS integration.

A lightweight binary diff format and versioning system for content files, designed for custom CMS integration. It supports per-file version indexing, content and metadata diffing, and bundling of revisions into structured barrels. Optimized for fast processing with lightweight checksums and compact binary layout, while retaining logical traceability.

• Name:
  • Common: Vermay
  • Kana-rep.: ファーメィ
  • Han-rep.： 華梅 (ja: かばい, zh: Huáméi)
  • Full: Version Management Format for Articles withby YAML front-matter Markdown
• File Extension:
  • Index Barrel: *.ivb
  • Diff Barrel: *.svb
• Mime Types:
  • Index Barrel: application/x-vermay-ib
  • Diff Barrel: application/x-vermay-sb
• Magic Number:
  • [0, 1] 0xbf, 0x80: BOM-like Bytes "뾀" pron "BBWAEL"(Barrel Bytes W Article Entry Leader)
  • [2, 3] 0x23, 0x21: Shebang-like ASCII "#!"
  • [4, 7] 0xb2, 0xda, 0xc7, 0xdf: EUC-JP "華梅" pron "huamei"
  • [8, 11] 0x89, 0xd8, 0x94, 0x7e: Shift-JIS "華梅" pron "huamei"
  • [12, 13] 0x00, 0x01: 2-bytes Unsigned Integer 1
  • [14] 0xbb: JIS X 0201 "さ" pron "sa" (for Index Barrel only)
  • [14] 0xc0: JIS X 0201 "た" pron "ta" (for Diff Barrel only)
  • [15] 0x3a: ASCII ":"

The official logographic representation (in Han characters) of Vermay is 華梅, chosen for two reasons:

1. Phonetic closeness:

• In Mandarin Chinese, Huáméi (華梅) is phonetically approximate to the intended reading Vermay.

1. Symbolic semantics:

• 華 (huá): meaning "splendid", "elegant", or "Chinese".
• 梅 (méi): meaning "plum", a symbol of perseverance and refinement.

This makes 華梅 both a phonetic transliteration and a meaningful logographic representation — a double-origin name that expresses the elegance and strength of the format itself.

Overview on Data Structure

<diff-barrel> := <file-diff>* <checksum>
<file-diff> := <file-hash-id> <file-meta> <version-index> <bandle-versions> <single-versions>
<file-meta> := <file-name> <location-path> <created-at> <last-updated-at>
<version-index> := ((single | bandle) <hash-id> <datetime>)*
<bandle-versions> := <version>*
<single-versions> := <version>*
<version> := <hash-id> <datetime> <matter-diff>* <content-diff>* <checksum>
<matter-diff> := <yaml-path> (((cr | ud) <value>) | rm)
<content-diff> := <line> (del <position> <length>)* (ins <position> <value>)*

※Needless to say, variable items ― such as repeated entries and added values ― are prepended with their length or count, though.