Search Flow

A keystroke travels webview → host → daemon, and results stream back the same way in batches.

sequenceDiagram
  autonumber
  participant W as Webview
  participant H as Extension host
  participant D as Daemon
  participant E as Engine

  W->>W: debounce (typingDelayMs)
  W->>H: query.changed {text, cursor, seq}
  H->>D: query/parse {text, cursor, openFiles}
  D-->>H: ParsedQuery + completions
  H-->>W: parse.result {seq}
  Note over W: chips, errors, autocomplete
  H->>D: $/cancelRequest (previous search)
  H->>D: search/start {searchId, text, openFiles}
  D->>D: re-parse text, plan
  D->>E: run Plan on published snapshot
  loop up to 200 items per batch
    E-->>D: ResultItems
    D-->>H: search/batch
    H-->>W: search.batch {seq}
  end
  D-->>H: search/start result {total, truncated, ms}
  H-->>W: search.done {seq}

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What keeps it correct

• Stale responses are dropped. Every message carries the keystroke's seq; the webview ignores anything older than the newest it sent.
• Every keystroke cancels the last search. Daemon loops check ctx.Done().
• The daemon re-parses. search/start takes text, not an AST, so the daemon never trusts a parse it didn't make.
• Searches read snapshots. The indexer publishes complete indexes in one step, so a search never sees a half-written one.
• Pages never overlap. In best-match order the engine sorts candidate files by what it knows before reading them (definitions, file names, open and recently changed files, tests, vendored and generated code), then scans them in that order, so the Nth result is the same whichever page asks for it. How well lines match only reorders files within a page, which is held until it is full or 50 ms have passed.

Selecting and opening

sequenceDiagram
  participant W as Webview
  participant H as Extension host
  participant D as Daemon
  W->>H: result.select {ref}
  H->>D: preview/get {ref}
  D-->>H: Preview
  H-->>W: preview.result
  W->>H: result.open {ref, where, position?}
  H->>D: open/resolve {ref}
  D-->>H: path + line, or repo + sha
  H->>H: open editor or commit diff

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ref is opaque outside the daemon: hosts and webviews pass it back unchanged.

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Next: Indexing: how the indexes are built and kept fresh.