perf(core): cache git discovery in Project.resolve by metadata fingerprint

packages/core/src/git.ts

@@ -1,5 +1,6 @@
 export * as Git from "./git.js"
 
+import os from "os"
 import path from "path"
 import { Cause, Context, Effect, Exit, Layer, Option, Schedule, Schema } from "effect"
 import { ChildProcess } from "effect/process"
@@ -80,6 +81,13 @@ export class OperationError extends Schema.TaggedError<OperationError>()("Git.Op
   cause: Schema.optional(Schema.Defect()),
 }) {}
 
+/** Git could not answer: the spawn failed or it exited with an unexpected status. */
+export class CommandError extends Schema.TaggedError<CommandError>()("Git.CommandError", {
+  args: Schema.Array(Schema.String),
+  exitCode: Schema.optional(Schema.Number),
+  cause: Schema.optional(Schema.Defect()),
+}) {}
+
 export class Worktree extends Schema.Class<Worktree>("Git.Worktree")({
   directory: AbsolutePath,
   kind: Schema.Literals(["main", "linked"]),
@@ -96,6 +104,11 @@ export class WorktreeError extends Schema.TaggedError<WorktreeError>()("Git.Work
 export interface Interface {
   readonly repo: {
     readonly discover: (input: AbsolutePath) => Effect.Effect<Repository | undefined>
+    /**
+     * Spawn-free stamp of the metadata that `discover`, `remote.get` and `history.rootCommits`
+     * read for the `.git` entry at `dotGit`: undefined when it isn't a readable repository.
+     */
+    readonly fingerprint: (dotGit: AbsolutePath) => Effect.Effect<string | undefined>
     readonly clone: (input: {
       remote: string
       directory: AbsolutePath
@@ -109,13 +122,15 @@ export interface Interface {
     }) => Effect.Effect<Repository, OperationError>
   }
   readonly remote: {
-    readonly get: (repository: Repository, name?: string) => Effect.Effect<string | undefined>
+    /** Undefined when the remote doesn't exist. */
+    readonly get: (repository: Repository, name?: string) => Effect.Effect<string | undefined, CommandError>
   }
   readonly history: {
     readonly head: (repository: Repository) => Effect.Effect<string | undefined>
     readonly branch: (repository: Repository) => Effect.Effect<string | undefined>
     readonly defaultRemoteBranch: (repository: Repository, remote?: string) => Effect.Effect<string | undefined>
-    readonly rootCommits: (repository: Repository) => Effect.Effect<readonly string[]>
+    /** Empty when HEAD is unborn. */
+    readonly rootCommits: (repository: Repository) => Effect.Effect<readonly string[], CommandError>
   }
   readonly sync: {
     readonly fetchRemotes: (repository: Repository, input?: { prune?: boolean }) => Effect.Effect<void, OperationError>
@@ -215,20 +230,77 @@ const layer = Layer.effect(
       })
     })
 
+    const stamp = (target: string) =>
+      fs.stat(target).pipe(
+        Effect.map((info) =>
+          [info.type, Option.getOrUndefined(info.ino), info.size, Option.getOrUndefined(info.mtime)?.getTime()].join(
+            ":",
+          ),
+        ),
+        Effect.orElseSucceed(() => "missing"),
+      )
+    const readText = (target: string) => fs.readFileStringSafe(target).pipe(Effect.orElseSucceed(() => undefined))
+
+    // Covers linked worktrees (gitdir file + commondir), HEAD and the ref it points at,
+    // loose/packed/reftable refs, repository/worktree/global/XDG/system config, and the
+    // cached `opencode` project id, so external `git init`, a first commit or `git remote`
+    // edits change the stamp.
+    const fingerprint = Effect.fn("Git.repo.fingerprint")(function* (dotGit: AbsolutePath) {
+      const dot = yield* fs.stat(dotGit).pipe(Effect.orElseSucceed(() => undefined))
+      if (!dot || (dot.type !== "File" && dot.type !== "Directory")) return undefined
+      const gitFile = dot.type === "File" ? (yield* readText(dotGit))?.match(/^gitdir:\s*(.+)$/m)?.[1]?.trim() : ""
+      if (gitFile === undefined) return undefined
+      const gitDir = gitFile ? yield* fs.resolve(path.resolve(path.dirname(dotGit), gitFile)) : dotGit
+      const commondir = (yield* readText(path.join(gitDir, "commondir")))?.trim()
+      const commonDir = commondir ? yield* fs.resolve(path.resolve(gitDir, commondir)) : gitDir
+      const head = (yield* readText(path.join(gitDir, "HEAD")))?.trim()
+      if (head === undefined) return undefined
+      const ref = head.startsWith("ref:") ? head.slice(4).trim() : undefined
+
+      const home = process.env.HOME || os.homedir()
+      const nosystem = ["1", "true", "yes", "on"].includes((process.env.GIT_CONFIG_NOSYSTEM ?? "").toLowerCase())
+      const files = [
+        path.join(gitDir, "HEAD"),
+        path.join(commonDir, "config"),
+        path.join(commonDir, "config.worktree"),
+        path.join(gitDir, "config.worktree"),
+        path.join(commonDir, "packed-refs"),
+        path.join(commonDir, "reftable", "tables.list"),
+        path.join(commonDir, "opencode"),
+        ...(ref ? [path.join(commonDir, ref), path.join(gitDir, ref)] : []),
+        process.env.GIT_CONFIG_GLOBAL || path.join(home, ".gitconfig"),
+        path.join(process.env.XDG_CONFIG_HOME || path.join(home, ".config"), "git", "config"),
+        ...(nosystem ? [] : [process.env.GIT_CONFIG_SYSTEM || "/etc/gitconfig"]),
+      ]
+      const stamps = yield* Effect.forEach([dotGit, ...files], stamp, { concurrency: "unbounded" })
+      return [gitDir, commonDir, head, ...files, ...stamps].join("\0")
+    })
+
+    const command = (cwd: string, args: string[]) =>
+      execute(cwd, proc, args).pipe(Effect.mapError((cause) => new CommandError({ args, cause })))
+
     const remote = Effect.fn("Git.remote.get")(function* (repository: Repository, name = "origin") {
-      const result = yield* run(repository.worktree, proc, ["remote", "get-url", name])
-      if (result.exitCode !== 0) return undefined
+      const args = ["remote", "get-url", name]
+      const result = yield* command(repository.worktree, args)
+      // Exit 2: no such remote.
+      if (result.exitCode === 2) return undefined
+      if (result.exitCode !== 0) return yield* new CommandError({ args, exitCode: result.exitCode })
       return result.text.trim() || undefined
     })
 
     const roots = Effect.fn("Git.history.rootCommits")(function* (repository: Repository) {
-      const result = yield* run(repository.worktree, proc, ["rev-list", "--max-parents=0", "HEAD"])
-      if (result.exitCode !== 0) return []
-      return result.text
-        .split("\n")
-        .map((item) => item.trim())
-        .filter(Boolean)
-        .toSorted()
+      const args = ["rev-list", "--max-parents=0", "HEAD"]
+      const result = yield* command(repository.worktree, args)
+      if (result.exitCode === 0)
+        return result.text
+          .split("\n")
+          .map((item) => item.trim())
+          .filter(Boolean)
+          .toSorted()
+      // `rev-parse -q --verify` exits 1 only when HEAD doesn't resolve, i.e. it is unborn.
+      const verify = yield* command(repository.worktree, ["rev-parse", "-q", "--verify", "HEAD"])
+      if (verify.exitCode === 1) return []
+      return yield* new CommandError({ args, exitCode: result.exitCode })
     })
 
     const head = Effect.fn("Git.history.head")(function* (repository: Repository) {
@@ -1291,7 +1363,7 @@ const layer = Layer.effect(
     })
 
     return Service.of({
-      repo: { discover, clone, create },
+      repo: { discover, fingerprint, clone, create },
       remote: { get: remote },
       history: { head, branch, defaultRemoteBranch: remoteHead, rootCommits: roots },
       sync: { fetchRemotes: fetch, fetchBranch, checkoutRemoteBranch: checkout, resetHard: reset },

packages/core/src/project.ts

@@ -1,6 +1,6 @@
 export * as Project from "./project.js"
 
-import { Context, Duration, Effect, Layer, Schedule, Schema } from "effect"
+import { Cache, Context, Duration, Effect, Layer, Schedule, Schema } from "effect"
 import { ChildProcess } from "effect/process"
 import { and, asc, desc, eq, gte, isNotNull, isNull, lt, lte, ne, sql } from "drizzle-orm"
 import path from "path"
@@ -320,6 +320,44 @@ const layer = Layer.effect(
       return root ? ID.make(root) : undefined
     })
 
+    // Failures resolve like dev (no remote / no root / own worktree) but aren't cached.
+    const gitDiscover = Effect.fnUntraced(function* (dotGit: AbsolutePath) {
+      const repo = yield* git.repo.discover(AbsolutePath.make(path.dirname(dotGit)))
+      if (!repo) return { resolved: undefined, cacheable: false }
+      let cacheable = true
+      const fallback = <A>(value: A) =>
+        Effect.orElseSucceed(() => {
+          cacheable = false
+          return value
+        })
+      const previous = yield* cached(repo.commonDirectory)
+      const id =
+        (yield* remote(repo).pipe(fallback(undefined))) ??
+        previous ??
+        (yield* rootCommit(repo).pipe(fallback(undefined)))
+      const canonical =
+        repo.gitDirectory === repo.commonDirectory
+          ? repo.worktree
+          : yield* git.worktree.list(repo).pipe(
+              Effect.map((items) => items.find((item) => item.kind === "main")?.directory ?? repo.worktree),
+              fallback(repo.worktree),
+            )
+      const resolved: Resolved = {
+        previous,
+        id: id ?? ID.global,
+        directory: repo.worktree,
+        canonical,
+        vcs: { type: "git" as const, store: repo.commonDirectory },
+      }
+      return { resolved, cacheable }
+    })
+
+    // Keyed by `.git` path plus its metadata fingerprint, so repeat resolves spawn no git.
+    const gitCache = yield* Cache.make({
+      capacity: 512,
+      lookup: (key: string) => gitDiscover(AbsolutePath.make(key.slice(0, key.indexOf("\u0000")))),
+    })
+
     // Mercurial identity uses the cached ID or the first root changeset; remote-derived
     // identity (the git `remote()` path) is a follow-up.
     const hgRoot = Effect.fnUntraced(function* (worktree: AbsolutePath) {
@@ -362,27 +400,16 @@ const layer = Layer.effect(
         Effect.map((matches) => matches[0]),
         Effect.orElseSucceed(() => undefined),
       )
-      const repo =
-        native && path.basename(native) === ".git"
-          ? yield* git.repo.discover(AbsolutePath.make(path.dirname(native)))
-          : undefined
-      if (repo) {
-        const previous = yield* cached(repo.commonDirectory)
-        const id = (yield* remote(repo)) ?? previous ?? (yield* rootCommit(repo))
-        const canonical =
-          repo.gitDirectory === repo.commonDirectory
-            ? repo.worktree
-            : yield* git.worktree.list(repo).pipe(
-                Effect.map((items) => items.find((item) => item.kind === "main")?.directory ?? repo.worktree),
-                Effect.orElseSucceed(() => repo.worktree),
-              )
-        return yield* save({
-          previous,
-          id: id ?? ID.global,
-          directory: repo.worktree,
-          canonical,
-          vcs: { type: "git" as const, store: repo.commonDirectory },
-        })
+      if (native && path.basename(native) === ".git") {
+        const dotGit = AbsolutePath.make(native)
+        const fingerprint = yield* git.repo.fingerprint(dotGit)
+        const key = `${dotGit}\u0000${fingerprint}`
+        const discovered = fingerprint
+          ? yield* Cache.get(gitCache, key).pipe(
+              Effect.tap((entry) => (entry.cacheable ? Effect.void : Cache.invalidate(gitCache, key))),
+            )
+          : yield* gitDiscover(dotGit)
+        if (discovered.resolved) return yield* save(discovered.resolved)
       }
 
       const hg = native && path.basename(native) === ".hg" ? yield* hgDiscover(AbsolutePath.make(native)) : undefined

packages/core/src/repository-cache.ts

@@ -136,7 +136,9 @@ const layer = Layer.effect(
               yield* cacheOperation(fs.ensureDir(path.dirname(localPath)), "ensure cache directory", localPath)
 
               const existing = yield* git.repo.discover(AbsolutePath.make(localPath))
-              const origin = existing ? yield* git.remote.get(existing) : undefined
+              const origin = existing
+                ? yield* git.remote.get(existing).pipe(Effect.orElseSucceed(() => undefined))
+                : undefined
               const originReference = origin ? Repository.parse(origin) : undefined
               // Discovery walks upward, so an enclosing repository with a
               // matching origin could masquerade as the cache entry; reuse

packages/core/test/fixture/spawn.ts

@@ -0,0 +1,24 @@
+import { Effect, Layer, PlatformError } from "effect"
+import { ChildProcessSpawner } from "effect/process"
+import { CrossSpawnSpawner } from "@opencode/util/cross-spawn-spawner"
+
+/** Counts process spawns; `fail` rejects matching spawns with a transient error. */
+export function countingSpawner(fail?: (args: readonly string[]) => boolean) {
+  const state = { spawns: 0 }
+  const node = CrossSpawnSpawner.node.replace(
+    CrossSpawnSpawner.node.mapLayer((base) =>
+      Layer.effect(
+        ChildProcessSpawner.ChildProcessSpawner,
+        Effect.map(ChildProcessSpawner.ChildProcessSpawner, (spawner) =>
+          ChildProcessSpawner.make((command) => {
+            state.spawns++
+            if (fail && command._tag === "StandardCommand" && fail(command.args))
+              return Effect.fail(PlatformError.systemError({ _tag: "Busy", module: "ChildProcess", method: "spawn" }))
+            return spawner.spawn(command)
+          }),
+        ),
+      ).pipe(Layer.provide(base)),
+    ),
+  )
+  return { node, spawns: () => state.spawns }
+}

packages/core/test/git.test.ts

@@ -7,7 +7,7 @@ import { LayerNode } from "@opencode/util/effect/layer-node"
 import { Git } from "@opencode/core/git"
 import { AbsolutePath, RelativePath } from "@opencode/core/schema"
 import { VcsPatch } from "@opencode/core/vcs/patch"
-import { branch, commit, initRepo, read, withRemote } from "./fixture/git"
+import { branch, commit, initGit, initRepo, read, withRemote } from "./fixture/git"
 import { tmpdir } from "./fixture/tmpdir"
 import { testEffect } from "./lib/effect"
 
@@ -103,6 +103,51 @@ describe("Git worktrees", () => {
       expect((yield* git.worktree.list(repo)).some((entry) => entry.directory.endsWith("-git-worktree"))).toBe(false)
     }),
   )
+
+  it.live("reads no remote and no root commits from an unborn repository", () =>
+    Effect.gen(function* () {
+      const root = yield* Effect.acquireRelease(
+        Effect.promise(() => tmpdir()),
+        (dir) => Effect.promise(() => dir[Symbol.asyncDispose]()),
+      )
+      yield* Effect.promise(() => initGit(root.path))
+      const git = yield* Git.Service
+      const repo = yield* git.repo.discover(AbsolutePath.make(root.path))
+      if (!repo) throw new Error("Repository not found")
+      expect(yield* git.remote.get(repo)).toBeUndefined()
+      expect(yield* git.history.rootCommits(repo)).toEqual([])
+    }),
+  )
+
+  it.live("fingerprint changes with repository metadata, including from a linked worktree", () =>
+    Effect.gen(function* () {
+      const root = yield* Effect.acquireRelease(
+        Effect.promise(() => tmpdir()),
+        (dir) => Effect.promise(() => dir[Symbol.asyncDispose]()),
+      )
+      const main = path.join(root.path, "main")
+      const linked = path.join(root.path, "linked")
+      yield* Effect.promise(() => initGit(main))
+      const git = yield* Git.Service
+      const fingerprint = (dir: string) => git.repo.fingerprint(AbsolutePath.make(path.join(dir, ".git")))
+
+      expect(yield* fingerprint(root.path)).toBeUndefined()
+      const unborn = yield* fingerprint(main)
+      expect(unborn).toBeDefined()
+      expect(yield* fingerprint(main)).toBe(unborn)
+
+      yield* Effect.promise(() => $`git commit --allow-empty -qm root`.cwd(main).quiet())
+      const committed = yield* fingerprint(main)
+      expect(committed).not.toBe(unborn)
+
+      yield* Effect.promise(() => $`git worktree add -q ${linked}`.cwd(main).quiet())
+      const before = yield* fingerprint(linked)
+      expect(before).toBeDefined()
+      yield* Effect.promise(() => $`git remote add origin git@github.com:owner/repo.git`.cwd(main).quiet())
+      expect(yield* fingerprint(main)).not.toBe(committed)
+      expect(yield* fingerprint(linked)).not.toBe(before)
+    }),
+  )
 })
 
 describe("Git trees", () => {