feat(nwsync): emit blobs and per-artifact NSYM, assemble merged manifests (#71)

Builds sow-tools#53. Format spec followed is the resolution comment of sow-platform#94, checked line by line against niv/neverwinter.nim at HEAD (`nwsync.nim`, `compressedbuf.nim`, `nwsync/private/libupdate.nim`).

## What lands

`crucible nwsync emit <artifact> --out DIR` — explodes one `.hak`/`.erf`, or one loose file such as the TLK, into NWSync blobs plus a NSYM v3 manifest covering only that artifact, with the same `.json` sidecar upstream writes. Blob path `data/sha1/<h0h1>/<h2h3>/<sha1>`, body in NWCompressedBuffer framing (magic `NSYC`, version 3, algorithm 2, uncompressed size, zstd header version 1, dictionary 0, raw zstd frame). The sha1 that names a blob is over the uncompressed bytes.

`crucible nwsync assemble --order NAMES --entries DIR --out DIR [--group-id N]` — merges the per-artifact manifests into one, reading no bulk data at all. Merge rule is resref shadowing, not concatenation: a resref in more than one artifact resolves to the earliest artifact in `--order`, which is how the game resolves it. `--group-id` stays caller-supplied (1 current, 2 testing; 0 is absent, matching upstream omitting a zero integer meta field).

Rules taken from upstream and not re-invented: `nss`/`ndb`/`gic` always skipped; an unresolvable restype is a hard error, not a skip; a resource over 15 MB fails closed; no `latest` file and no `.origin` file, ever. A `.mod` is refused outright — a persistent world publishes no module contents, so the module contributes no bytes.

## Two deliberate departures

- **Emitter version is its own field, not the build revision.** `emitter_version` is a constant bumped only when emitted bytes change. Keying the refuse-to-merge check on `created_with` would invalidate every published index on every unrelated crucible commit and force a re-emit of the whole 15 GB corpus — the opposite of "nothing downstream ever needs the hak again".
- **`SOURCE_DATE_EPOCH` pins the sidecar timestamp.** The manifest itself was already deterministic; the sidecar's `created` was not, against the determinism rule in `docs/consumer-contract.md`.

## Not in this PR, and why

- **Direct upload.** Only the local `--out` sink exists, which is the conformance path. The upload sink and the mid-hak-failure question are sow-tools#60, and the consumer wiring is #65.
- **The conformance run against upstream.** sow-tools#59 owns getting `nwn_nwsync_write` running and capturing reference output. The format here was read from upstream source rather than from its output, so the byte-for-byte manifest comparison and the after-decompression blob comparison still have to happen — that is what #59 is for. The tests in this PR check the layout against the spec, so a shared misreading would pass them.
- **The `artifacts/haks/sha256/<a>/<b>/<sha256>.nsym` location.** emit writes `<out>/<name>.nsym`; where a publisher puts it is the publisher's business (#65).
- **The acceptance gate** — a real client syncing from an assembled manifest — is unchanged and still open.

## Checks

`make check` green (vet, unit tests, shellcheck, yamllint, workflow contract), `make smoke` green with the new builder, `nix build .#crucible` produces `crucible-nwsync`.

🤖 Generated with [Claude Code](https://claude.com/claude-code)Reviewed-on: #71

Co-authored-by: vickydotbat <vickydotbat@tutamail.com>
This commit was merged in pull request #71.
This commit is contained in:
2026-07-29 10:50:05 +00:00
committed by archvillainette
parent 4d03085996
commit a131b25e5b
15 changed files with 1265 additions and 8 deletions
+200
View File
@@ -0,0 +1,200 @@
package nwsync
import (
"bytes"
"encoding/binary"
"encoding/hex"
"encoding/json"
"fmt"
"io"
"path/filepath"
"sort"
"strings"
)
// NSYM manifest, version 3, exactly as upstream neverwinter/nwsync.nim writes
// it. Everything is little-endian:
//
// "NSYM", uint32 version, uint32 entry count, uint32 mapping count,
// entries: byte[20] raw sha1, uint32 size, char[16] resref, uint16 restype
// mappings: uint32 entry index, char[16] resref, uint16 restype
//
// Entries are sorted by lowercase sha1 hex then resref, and a resource whose
// sha1 was already written becomes a mapping instead of a second entry.
const (
manifestVersion = 3
hashTreeDepth = 2
resRefBytes = 16
)
// Entry is one resource in a manifest.
type Entry struct {
SHA1 [20]byte
Size uint32
ResRef string // lowercase, no extension, at most 16 characters
ResType uint16
}
func (e Entry) sha1Hex() string { return hex.EncodeToString(e.SHA1[:]) }
// Identity is what a resref resolves by: name plus type. It is the merge key
// inside one artifact and across artifacts alike.
type Identity struct {
ResRef string
ResType uint16
}
func (e Entry) identity() Identity { return Identity{ResRef: e.ResRef, ResType: e.ResType} }
// writeManifest serialises entries into NSYM v3 bytes.
func writeManifest(entries []Entry) ([]byte, error) {
sorted := make([]Entry, len(entries))
copy(sorted, entries)
sort.SliceStable(sorted, func(i, j int) bool {
left, right := sorted[i].sha1Hex(), sorted[j].sha1Hex()
if left != right {
return left < right
}
return sorted[i].ResRef < sorted[j].ResRef
})
var body, mappings bytes.Buffer
seen := make(map[string]uint32, len(sorted))
var entryCount, mappingCount uint32
for _, entry := range sorted {
padded, err := padResRef(entry.ResRef)
if err != nil {
return nil, err
}
if index, ok := seen[entry.sha1Hex()]; ok {
_ = binary.Write(&mappings, binary.LittleEndian, index)
mappings.Write(padded)
_ = binary.Write(&mappings, binary.LittleEndian, entry.ResType)
mappingCount++
continue
}
seen[entry.sha1Hex()] = entryCount
entryCount++
body.Write(entry.SHA1[:])
_ = binary.Write(&body, binary.LittleEndian, entry.Size)
body.Write(padded)
_ = binary.Write(&body, binary.LittleEndian, entry.ResType)
}
var out bytes.Buffer
out.WriteString("NSYM")
for _, field := range []uint32{manifestVersion, entryCount, mappingCount} {
_ = binary.Write(&out, binary.LittleEndian, field)
}
out.Write(body.Bytes())
out.Write(mappings.Bytes())
return out.Bytes(), nil
}
// readManifest parses NSYM v3 bytes. Mappings are expanded back into entries,
// the way upstream's reader does, so a caller sees one entry per resref.
func readManifest(data []byte) ([]Entry, error) {
reader := bytes.NewReader(data)
magic := make([]byte, 4)
if _, err := io.ReadFull(reader, magic); err != nil || string(magic) != "NSYM" {
return nil, fmt.Errorf("not a manifest (invalid magic bytes)")
}
var version, entryCount, mappingCount uint32
for _, field := range []*uint32{&version, &entryCount, &mappingCount} {
if err := binary.Read(reader, binary.LittleEndian, field); err != nil {
return nil, fmt.Errorf("truncated manifest header: %w", err)
}
}
if version != manifestVersion {
return nil, fmt.Errorf("unsupported manifest version %d", version)
}
entries := make([]Entry, 0, entryCount+mappingCount)
for i := uint32(0); i < entryCount; i++ {
var entry Entry
if _, err := io.ReadFull(reader, entry.SHA1[:]); err != nil {
return nil, fmt.Errorf("truncated entry %d: %w", i, err)
}
if err := binary.Read(reader, binary.LittleEndian, &entry.Size); err != nil {
return nil, fmt.Errorf("truncated entry %d: %w", i, err)
}
resref, restype, err := readResRef(reader)
if err != nil {
return nil, fmt.Errorf("truncated entry %d: %w", i, err)
}
entry.ResRef, entry.ResType = resref, restype
entries = append(entries, entry)
}
for i := uint32(0); i < mappingCount; i++ {
var index uint32
if err := binary.Read(reader, binary.LittleEndian, &index); err != nil {
return nil, fmt.Errorf("truncated mapping %d: %w", i, err)
}
if index >= entryCount {
return nil, fmt.Errorf("mapping %d references non-existent entry %d", i, index)
}
resref, restype, err := readResRef(reader)
if err != nil {
return nil, fmt.Errorf("truncated mapping %d: %w", i, err)
}
target := entries[index]
entries = append(entries, Entry{SHA1: target.SHA1, Size: target.Size, ResRef: resref, ResType: restype})
}
return entries, nil
}
func readResRef(reader *bytes.Reader) (string, uint16, error) {
raw := make([]byte, resRefBytes)
if _, err := io.ReadFull(reader, raw); err != nil {
return "", 0, err
}
var restype uint16
if err := binary.Read(reader, binary.LittleEndian, &restype); err != nil {
return "", 0, err
}
return strings.ToLower(string(bytes.TrimRight(raw, "\x00"))), restype, nil
}
func padResRef(resref string) ([]byte, error) {
if len(resref) > resRefBytes {
return nil, fmt.Errorf("resref %q exceeds %d characters", resref, resRefBytes)
}
padded := make([]byte, resRefBytes)
copy(padded, strings.ToLower(resref))
return padded, nil
}
// Sidecar is the .json file written next to every manifest. Clients fetch it
// (nwn_nwsync_fetch.nim), so the field names and order match upstream.
// Upstream omits an integer meta field whose value is 0, hence group_id's
// omitempty: 0 means absent, not "group zero".
type Sidecar struct {
Version int `json:"version"`
SHA1 string `json:"sha1"`
HashTreeDepth int `json:"hash_tree_depth"`
ModuleName string `json:"module_name"`
Description string `json:"description"`
IncludesModuleContents bool `json:"includes_module_contents"`
IncludesClientContents bool `json:"includes_client_contents"`
TotalFiles int `json:"total_files"`
TotalBytes int64 `json:"total_bytes"`
OnDiskBytes int64 `json:"on_disk_bytes"`
Created int64 `json:"created"`
CreatedWith string `json:"created_with"`
EmitterVersion string `json:"emitter_version,omitempty"`
GroupID int `json:"group_id,omitempty"`
}
func marshalSidecar(sidecar Sidecar) ([]byte, error) {
body, err := json.MarshalIndent(sidecar, "", " ")
if err != nil {
return nil, err
}
// Upstream terminates the file with CRLF; match it.
return append(body, '\r', '\n'), nil
}
// blobPath is the data store path for a blob, hash tree depth 2.
func blobPath(root, sha1Hex string) string {
return filepath.Join(root, "data", "sha1", sha1Hex[0:2], sha1Hex[2:4], sha1Hex)
}