Documentation
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Overview ¶
Package filediff produces unified-diff text for files changed by an agent turn, using `git diff` against the workspace PVC's HEAD commit.
US-65.3 (opencode adapter) prototype — resolves design/0049 §10 open question: opencode's `session.diff` SSE event carries only the list of file paths (`properties.files: [...]`), not diff hunks. Producing the `Patch string` payload that pkg/session.FileDiff requires means running `git diff` against the changed paths in the workspace git repo.
Prerequisite: /workspace MUST be a git repo. Workspaces today start with whatever is on the PVC (possibly empty); a separate US-65.3 follow-up initializes /workspace as a git repo on workspace creation and commits after each agent turn so the next turn's diff has a base.
This package is the thin pure-Go shell around `git diff` — it does not own the commit cadence, the repo initialization, or the translation to pkg/session.FileDiff. Those are the adapter's job.
Index ¶
Constants ¶
const MaxDiffBytes = 1 << 20 // 1 MiB
MaxDiffBytes bounds the size of one file's unified-diff output. A 1 MiB cap covers realistic source-file changes (a 10k-line file fully rewritten is ~600 KB of diff) while preventing a runaway tool that rewrites node_modules from blowing up the event stream. Files whose diff exceeds this are returned with Patch="" and Truncated=true (signaled by git diff's exit code 0 + output containing the ".../.../... file too large" marker — see ResolveLargeFiles).
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Diff ¶
Diff is the unified-diff text for one file's changes against HEAD. Path is repo-relative (e.g. "src/foo.go"); Patch is the unified-diff text (empty if the file is binary, missing, or exceeded MaxDiffBytes).
type Producer ¶
type Producer struct {
// contains filtered or unexported fields
}
Producer runs `git diff` against a workspace PVC git repo. Construct once per workspace; safe for concurrent use (git is invoked via exec.CommandContext which is goroutine-safe).
func NewProducer ¶
NewProducer constructs a Producer for the workspace at workspaceRoot. Returns an error if workspaceRoot is not absolute (git -C requires absolute or root-relative paths and relative paths invite CWD races).
func (*Producer) DiffFiles ¶
DiffFiles produces unified-diff text for each path in files against HEAD. Returns one Diff per path that has a measurable change; paths that did not change (e.g. opencode reported them but git sees no diff vs HEAD) are omitted from the result.
files MUST be repo-relative paths (e.g. "src/foo.go", not "/workspace/src/foo.go"). The Producer does not rewrite them; git interprets pathspecs relative to the repo root regardless of -C.
Empty files slice returns (nil, nil) — no work to do.
New (untracked) files in `files` are normalized via `git add -N` (intent-to-add) before diffing. Without this, `git diff HEAD -- new.txt` returns empty for untracked files — git treats them as outside the index. `git add -N` records the path in the index with no content, so `git diff HEAD` correctly shows the addition vs /dev/null. The intent-to-add marker is local to the index; it does not stage the file's content for commit.
On git binary missing or repo corruption, returns a non-nil error. A truncated diff for one large file does NOT fail the call; that file's Diff has Truncated semantics via Patch="..." (truncation is per-file, not per-call).
Source Files