rules

Documentation

Overview

Package rules holds the small rules every thread.Storage backend must answer identically: the List limit, the metadata and title filters, the paging cursor, and the line discipline of a session's bytes. Memory and jsonl call these directly; a backend outside the thread module (sqlite) keeps its own copy, and the threadtest conformance table pins every copy to one answer.

The package imports nothing from thread — thread imports it — so the rules speak in plain values: maps, byte slices, times and ids.

Index

• Constants
• func AfterCursor(created time.Time, id string, before time.Time, beforeID string) bool
• func CloneMeta(kv map[string]string) map[string]string
• func CompareNewestFirst(aCreated time.Time, aID string, bCreated time.Time, bID string) int
• func CompleteLen(b []byte) int
• func InfoTitle(line []byte) string
• func LimitOf(n int) int
• func MetaMatch(meta, want map[string]string) bool
• func SplitLines(b []byte) [][]byte
• func TitleMatches(title, search string) bool
• func TitleOf(lines [][]byte) string
• func Torn(b []byte) bool

Constants

const (
	DefaultLimit = 50
	MaxLimit     = 500
)

The List page bounds: a zero or negative Query.Limit reads as DefaultLimit, and anything above MaxLimit clamps to it.

Functions

func AfterCursor

func AfterCursor(created time.Time, id string, before time.Time, beforeID string) bool

AfterCursor reports whether a session (created, id) lies strictly after the paging cursor (before, beforeID) in List order — newest first by created, ties by id descending. A zero before is no cursor: everything is after it. With a cursor, a session qualifies when it was created strictly before the cursor's time, or at exactly that time with an id strictly below beforeID; an empty beforeID therefore admits nothing from the cursor's own instant.

func CloneMeta

func CloneMeta(kv map[string]string) map[string]string

CloneMeta copies a metadata map so a header never aliases the caller's; an empty map clones to nil.

func CompareNewestFirst

func CompareNewestFirst(aCreated time.Time, aID string, bCreated time.Time, bID string) int

CompareNewestFirst orders two sessions for List: newest first by created, ties by id descending.

func CompleteLen

func CompleteLen(b []byte) int

CompleteLen returns the length of b's complete prefix: everything up to and including the last newline, 0 when b holds none. Truncating to it is the torn-tail repair.

func InfoTitle

func InfoTitle(line []byte) string

InfoTitle returns the title one entry line sets: non-empty only for an info entry that carries one.

func LimitOf

func LimitOf(n int) int

LimitOf normalizes Query.Limit: zero and negatives mean DefaultLimit, values above MaxLimit clamp.

func MetaMatch

func MetaMatch(meta, want map[string]string) bool

MetaMatch reports whether meta holds every pair of want, exactly: a wanted key must be present and carry the wanted value. An empty want matches everything.

func SplitLines

func SplitLines(b []byte) [][]byte

SplitLines splits on '\n', complete lines only: the bytes after the last newline, if any, are a torn tail and are not returned. The lines alias b.

func TitleMatches

func TitleMatches(title, search string) bool

TitleMatches reports whether the title contains the search as a substring, folding case.

func TitleOf

func TitleOf(lines [][]byte) string

TitleOf returns a session's current title from its entry lines: the last info entry carrying a non-empty title — the rule Session.Title answers with — or "" when none ever did. A line that does not decode is not a title.

func Torn

func Torn(b []byte) bool

Torn reports whether the bytes end mid-line: a writer cut before its newline. Bytes ending in '\n' — and no bytes at all — are complete.