4 Commits

Author	SHA1	Message	Date
clawbot	63fbc98e63	feat: cache size management and LRU eviction (closes #51) (#55) ... Implements #51 per the issue DoD and the owner direction comment (issuecomment-44068). ## Behavior **Config: `cache_max_bytes`** (integrates with the #52/#53 validation framework) - Strict int64 parsing via a new `getInt64`/`int64Val` getter in the existing strict-loader pattern; the key is registered in the known-keys list. A SET but invalid value — negative, float, null, non-numeric string, boolean, list — aborts startup with exit 1 naming the key and the offending value. - Explicit values are used exactly as given, any non-negative amount, no floor. `cache_max_bytes: 0` is a valid value that disables the disk cache entirely. - Omitted: after `state_dir` validation, the default resolves to `max(75% of free bytes on the filesystem containing &lt;state_dir&gt;/cache/, 500 MiB)`. The cache directory is created first and statfs runs on that actual path, so the measurement hits the right filesystem. The probe is injectable (`FreeSpaceProbeFunc`) so tests do not depend on the host disk. The effective limit (and disabled state) is logged at startup. **Size accounting** (no directory scans on the hot path) - Migration `002` adds a `variant_content` table — processed variants were previously untracked anywhere — and a `last_accessed_at` column on `source_content`, both indexed. Total usage is two SUM queries. - Stores record accounting rows; cache hits touch the LRU timestamps (same cost class as the existing per-request stats UPDATEs). The variant accounting insert is best-effort with a warning: the reconciliation pass (below) adopts any file that missed its row, and this keeps the pre-migration inline test schema working. **Eviction policy: global LRU across both content classes** - Candidates are the least-recently-used entries from `variant_content` and `source_content` (batched, 100 per class per pass, merged oldest-first by `COALESCE(last_accessed_at, fetched_at)`), evicted until usage is at or below the limit. - Why global LRU: recency of actual use is the best cheap predictor of future use for a CDN-style cache, and treating both classes in one ordering avoids pathologies of class-priority schemes (e.g. evicting every variant before any cold source blob, which would tank hit rate, or the reverse, which would hoard stale sources). Byte-for-byte, the coldest data goes first regardless of what kind it is. LFU-style schemes need more bookkeeping for marginal gain at this scale. - Reference safety (the multi-reference DoD case): evicting a source blob deletes ALL `source_metadata` rows referencing it plus its `source_content` row in a single transaction BEFORE the file is unlinked. A blob referenced by multiple source paths is only ever removed together with all of its references, and DB rows never point at deleted files (the crash window leaves at worst an orphaned file, which reconciliation sweeps). The JSON metadata sidecars for removed rows are deleted as well. **Triggers, off the request path** - A background goroutine (started in the handlers OnStart hook, stopped in OnStop) runs an eviction pass on a periodic ticker (5 min) and on write pressure: every store sends a non-blocking notification on a capacity-1 channel. Requests never wait on eviction. - On startup the goroutine first reconciles accounting with the disk (off the hot path): adopts untracked variant files (size/mtime from disk, content type from the `.meta` sidecar), drops accounting rows whose files are missing, removes source blob files the DB does not know (unreachable, since lookups go through `source_metadata`), removes rows whose files are gone, and sweeps `.tmp-*` files older than an hour. **`cache_max_bytes: 0` disables the disk cache** - No cache directories are created, lookups always miss, `StoreSource`/`StoreVariant` are no-ops, no evictor runs; every request fetches and processes uncached. Verified end-to-end (below). ## Notes for review - At the `imgcache.CacheConfig` layer, disabling is an explicit `DisableDiskCache` flag rather than `MaxBytes == 0`, because existing test fixtures construct `CacheConfig` without `MaxBytes` and rely on the legacy "no limit" behavior; per repo rules those tests were not touched. The config layer maps `cache_max_bytes: 0` to the flag in `handlers`. `MaxBytes == 0` at that layer means "no limit enforced" and is unreachable from production config (the computed default is always at least 500 MiB). - The negative cache stays active in disabled mode: it is DB-backed (TTL-expired rows in SQLite), not part of the disk cache this issue bounds, and it protects against hammering failing upstreams. Flagging explicitly since the direction said "no cache reads, no cache writes" — I read that as the disk cache; happy to disable it too if intended. - One deviation from pure red/green: after the red commit I extended the new-test fixture helper (`newEvictionTestCache`) to pass `DisableDiskCache: maxBytes == 0`, mirroring the production mapping, when the flag design emerged. Assertions were not touched; no pre-existing tests were modified. - Sidecar files (`.meta`, metadata JSON) are not counted in usage; they are bounded by entry counts and small (tens of bytes to ~1 KiB per entry) while content bytes dominate. Documented here for transparency. - Discovered while working: `Cache.Stats` reads the never-populated `output_content`/`request_cache` tables, so `TotalItems`/`TotalSizeBytes` are always 0. Out of scope here; filing as a separate issue. ## Verification - TDD: commit `3963ec3` adds the failing tests first (18 new tests covering strict parsing, default computation with injected probe including floor and 75% branches, explicit-no-floor, zero-disables, size accounting, dedup accounting, LRU order, multi-reference blob eviction with the no-dangling-references invariant, under-limit no-op, write-pressure trigger, periodic trigger, reconciliation); implementation follows in `8cb09b6`/`bdd86a4` until green. - `make check` green (all tests, lint 0 issues, fmt-check) at HEAD. - Pinned CI lint gate: `docker build --target lint .` green (golangci-lint v2.10.1). - End-to-end with the built binary: - omitted key: startup logs `computed default cache size limit from free space` and `effective cache size limit` (75% of the test host's free space); - `cache_max_bytes: banana`: exit 1 with `config key "cache_max_bytes": value "banana" is not an integer`; - `cache_max_bytes: 0`: `cache_disabled=true` logged, two identical requests both fetch upstream (2 upstream fetches logged), 200 `image/jpeg` responses, no `cache/` directory created, only `state.sqlite3` in the state dir; - enabled: second request served from cache (1 upstream fetch), `variant_content` and `source_content` rows match the on-disk file sizes. Co-authored-by: sneak <sneak@sneak.berlin> Reviewed-on: #55 Co-authored-by: clawbot <clawbot@noreply.example.org> Co-committed-by: clawbot <clawbot@noreply.example.org>	2026-08-09 13:22:51 +02:00
clawbot	7010d55d72	Move schema_migrations table creation into 000.sql (#36) ... ## Summary Moves the `schema_migrations` table definition from inline Go code into `internal/database/schema/000.sql`, so the migration tracking table schema lives alongside all other schema files. closes #29 ## Changes ### New file: `internal/database/schema/000.sql` - Contains the `CREATE TABLE IF NOT EXISTS schema_migrations` DDL - This is applied as a bootstrap step before the normal migration loop ### Refactored: `internal/database/database.go` - Removed the inline `CREATE TABLE IF NOT EXISTS schema_migrations` SQL from both `runMigrations` and `ApplyMigrations` - Added `bootstrapMigrationsTable()` which: - Checks `sqlite_master` to see if the table already exists - If missing: reads and executes `000.sql` to create it, then records version `000` - If present (backwards compat with existing DBs created by old inline code): back-fills version `000` so the normal loop skips the bootstrap file - Deduplicated: both `Database.runMigrations()` and the exported `ApplyMigrations()` now delegate to a single `applyMigrations()` helper - Added `logInfo`/`logDebug` helpers to handle the optional logger (nil when called from `ApplyMigrations` in tests) ### New file: `internal/database/database_test.go` - `TestApplyMigrations_CreatesSchemaAndTables` — verifies all migrations apply and all expected tables exist - `TestApplyMigrations_Idempotent` — verifies running migrations twice produces no errors or duplicates - `TestBootstrapMigrationsTable_FreshDatabase` — verifies bootstrap creates the table and records version 000 - `TestBootstrapMigrationsTable_ExistingTableBackwardsCompat` — verifies existing DBs (from old inline-SQL code) get version 000 back-filled without data loss ## Conflict note [PR #33](#33) (for [issue #28](#28)) is also modifying migration code. This PR is based on current `main` and the conflict will be resolved at merge time. Co-authored-by: user <user@Mac.lan guest wan> Co-authored-by: clawbot <clawbot@noreply.git.eeqj.de> Co-authored-by: clawbot <clawbot@sneak.berlin> Co-authored-by: clawbot <clawbot@eeqj.de> Co-authored-by: Jeffrey Paul <sneak@noreply.example.org> Reviewed-on: #36 Co-authored-by: clawbot <clawbot@noreply.example.org> Co-committed-by: clawbot <clawbot@noreply.example.org>	2026-03-25 02:20:52 +01:00
clawbot	9c29cb57df	feat: parse version prefix from migration filenames (#33) ... Closes #28 Migration filenames now follow the pattern `<version>_<description>.sql` (e.g. `001_initial_schema.sql`). The version stored in `schema_migrations` is the numeric prefix only, not the full filename stem. ## Changes - **`ParseMigrationVersion()`** — new exported function that extracts the numeric prefix from migration filenames. Validates that the prefix is purely numeric and rejects malformed filenames (empty prefix, non-numeric characters, leading underscore). - **Renamed `001.sql` → `001_initial_schema.sql`** — migration files can now have descriptive names while the tracked version remains `001`. This is safe pre-1.0.0 (no installed base). - **Deduplicated migration logic** — `runMigrations()` and `ApplyMigrations()` now share a single `applyMigrations()` implementation, plus extracted `collectMigrations()` and `ensureMigrationsTable()` helpers. - **Unit tests** — `TestParseMigrationVersion` covers valid patterns (version-only, with description, multi-digit, multiple underscores) and error cases (empty, leading underscore, non-numeric, mixed alphanumeric). `TestApplyMigrations` and `TestApplyMigrationsIdempotent` verify end-to-end migration application against an in-memory SQLite database. Co-authored-by: user <user@Mac.lan guest wan> Reviewed-on: #33 Co-authored-by: clawbot <clawbot@noreply.example.org> Co-committed-by: clawbot <clawbot@noreply.example.org>	2026-03-18 03:18:38 +01:00
sneak	4595929275	Add embedded SQL migrations system ... Migrations are stored in schema/*.sql and embedded via go:embed. Applied migrations are tracked in schema_migrations table. Initial schema includes source_content, source_metadata, output_content, request_cache, negative_cache, and cache_stats tables.	2026-01-08 03:35:43 -08:00