feat(fs): add a minimal read_image tool over the attachment and fs seams

The model reads a PNG/JPEG/WebP/GIF file, the bytes commit through the
durable attachment lifecycle, and the tool result carries the real
ImageBlock so the image enters context from the next request onward.
FileSystem gains a bounded readBytes primitive (local + E2B providers);
registration is conditional on the attachment store, and a strict
execution gate refuses routes that do not declare image input, so a
text route's durable history stays free of image blocks. llm-replay
models may declare inputModalities, letting keyless ACP snapshots pin
both the sha256-referenced success and the verbatim refusal.

Supersedes the withdrawn route-scoped design of PR #598; the decision
record is .agents/notes/implemented/feature/2026-08-10-minimal-read-image-tool.md.
This commit is contained in:
creatixchu
2026-08-10 15:09:07 +08:00
parent 3764ce62a5
commit 1861a3fc7c
65 changed files with 1973 additions and 67 deletions

View File

@@ -2,7 +2,7 @@
English | [中文](README.zh.md)
The **local-filesystem implementation** of the `ctx.fs` provider contract ([`@deepseek-ai/dsh-fs`](../fs)). Backs the eleven `FileSystem` primitives with the host filesystem; loading it as a plugin populates `ctx.fs`.
The **local-filesystem implementation** of the `ctx.fs` provider contract ([`@deepseek-ai/dsh-fs`](../fs)). Backs the twelve `FileSystem` primitives with the host filesystem; loading it as a plugin populates `ctx.fs`.
```ts ignore-check
import { LocalFileSystem } from '@deepseek-ai/dsh-fs-local'
@@ -18,6 +18,7 @@ await ctx.plugin(LocalFileSystem, { cwd: process.cwd() })
- **Execution-world coordinates** — `processPath` exposes the target's canonical host path, `fileUrl` encodes that path through Node's platform-aware URL conversion, and `contains` uses platform path semantics to test identity or descendant containment without consumers parsing `targetKey`.
- **`stat` / `lstat`** — return target metadata or `undefined` when absent. `stat` reports `FsInfo` for an already resolved target (`version` = an opaque token derived from bigint `dev:ino:size:mtimeNs:ctimeNs`, `type` of `file`/`directory`/`other`, byte `size`); path-shaped `lstat` reports `FsPathInfo` without following the final symlink and can therefore return `symlink`. Both check cancellation before and after their asynchronous metadata probe, so an abort that lands in flight reports `FS_ABORTED` rather than stale absence.
- **`readText` / `streamText`** — UTF-8 only. `readText` reads the whole file; `streamText` decodes chunks so a huge file need not be held whole in memory and consumers can enforce their own retention bounds. Both reject invalid UTF-8 and NUL-byte binary samples (`FS_NOT_TEXT`) and non-regular targets. The `read` tool (`@deepseek-ai/dsh-tool-fs`) owns line windowing.
- **`readBytes`** — raw whole-file bytes with no decoding or binary rejection (the `read_image` tool validates content through the attachment service). The required byte cap short-circuits on the stat size before any content I/O; the subsequent stream reads at most one byte beyond the cap, so a file growing after stat still fails `FS_TOO_LARGE` without unbounded buffering.
- **`listDir`** — lists one directory level in stable `name.localeCompare()` order. Each entry carries the child basename, type, resolved child target (`displayPath` under the listed directory, `targetKey` as the realpath identity), and cheap stat metadata (`version`, plus `size` for regular files). It never opens or decodes file contents. Missing targets report `FS_NOT_FOUND`, file/special-file targets report `FS_NOT_DIRECTORY`, aborted calls report `FS_ABORTED`, permission failures report `FS_PERMISSION_DENIED`, and other listing or child metadata I/O failures report `FS_IO_ERROR`. Broken/disappeared children are returned as `other` without metadata, but permission/IO failures while resolving a child fail the whole listing with a structured `FsError`.
- **`writeText`** — atomic: writes to a temp file opened exclusively (`wx`, `0o600`) inside a randomly-named private staging dir (`0o700`) next to the target, then fsyncs and publishes. An existing file's mode is preserved, while new files default to `0o600`; on Windows a new file inherits the destination directory's DACL, while replacement copies the target DACL onto the empty temp before writing and publishes through `ReplaceFileW` so the original access policy survives ([Windows DACL preservation Agent Note](../../../.agents/notes/implemented/bug-fix/2026-07-19-windows-atomic-write-dacl-preservation.md)). The `expected` guard is OPTIONAL: omitting it unconditionally creates-or-overwrites; `createIfAbsent` hard-links the staged file into place as an atomic no-replace publication, so a regular file created after the initial probe is preserved and rejected with `FS_NOT_OBSERVED`, while a non-regular path entry is preserved and rejected with `FS_NOT_REGULAR_FILE`; `replaceIfVersion` replaces only at the observed version (a missing target or mismatch is `FS_STALE_VERSION`).
- **`editText`** — atomic literal read-modify-write over the same primitive, serialized per target by a mutation lock. The `expected` guard is OPTIONAL: when supplied it verifies the version BEFORE literal matching (a stale edit reports `FS_STALE_VERSION`, never `FS_EDIT_NOT_FOUND`/`FS_AMBIGUOUS_EDIT` against newer content); omitting it edits the current content unconditionally. A missing target reports `FS_STALE_VERSION` either way. LF-normalizes for matching, restores the file's dominant CRLF/LF style, and rejects empty `oldString` / zero matches (`FS_EDIT_NOT_FOUND`) or ambiguous multi-matches without `replace_all` (`FS_AMBIGUOUS_EDIT`).