format/commitgraph: Split layer files

7 files changed, 238 insertions, 209 deletions

diff --git a/format/commitgraph/layer.go b/format/commitgraph/layer.go
new file mode 100644
index 00000000..3f6011cc
--- /dev/null
+++ b/format/commitgraph/layer.go
@@ -0,0 +1,28 @@
+package commitgraph
+
+import (
+	"os"
+
+	"codeberg.org/lindenii/furgit/format/commitgraph/bloom"
+)
+
+type layer struct {
+	path       string
+	file       *os.File
+	data       []byte
+	numCommits uint32
+	baseCount  uint32
+	globalFrom uint32
+
+	chunkOIDFanout    []byte
+	chunkOIDLookup    []byte
+	chunkCommit       []byte
+	chunkGeneration   []byte
+	chunkGenerationOv []byte
+	chunkExtraEdges   []byte
+	chunkBloomIndex   []byte
+	chunkBloomData    []byte
+	chunkBaseGraphs   []byte
+
+	bloomSettings *bloom.Settings
+}
diff --git a/format/commitgraph/layer_close.go b/format/commitgraph/layer_close.go
new file mode 100644
index 00000000..9b7dfbb0
--- /dev/null
+++ b/format/commitgraph/layer_close.go
@@ -0,0 +1,33 @@
+package commitgraph
+
+import "syscall"
+
+func closeLayers(layers []layer) {
+	for i := len(layers) - 1; i >= 0; i-- {
+		_ = layers[i].close()
+	}
+}
+
+func (layer *layer) close() error {
+	var closeErr error
+
+	if layer.data != nil {
+		err := syscall.Munmap(layer.data)
+		if err != nil {
+			closeErr = err
+		}
+
+		layer.data = nil
+	}
+
+	if layer.file != nil {
+		err := layer.file.Close()
+		if err != nil && closeErr == nil {
+			closeErr = err
+		}
+
+		layer.file = nil
+	}
+
+	return closeErr
+}
diff --git a/format/commitgraph/layer_lookup.go b/format/commitgraph/layer_lookup.go
new file mode 100644
index 00000000..3ae4ff53
--- /dev/null
+++ b/format/commitgraph/layer_lookup.go
@@ -0,0 +1,53 @@
+package commitgraph
+
+import (
+	"bytes"
+	"encoding/binary"
+
+	"codeberg.org/lindenii/furgit/internal/intconv"
+	"codeberg.org/lindenii/furgit/objectid"
+)
+
+func layerLookup(layer *layer, oid objectid.ObjectID) (uint32, bool) {
+	hashSize := oid.Size()
+	first := int(oid.RawBytes()[0])
+
+	var lo uint32
+	if first > 0 {
+		lo = binary.BigEndian.Uint32(layer.chunkOIDFanout[(first-1)*4 : first*4])
+	}
+
+	hi := binary.BigEndian.Uint32(layer.chunkOIDFanout[first*4 : (first+1)*4])
+	if hi == 0 || lo >= hi {
+		return 0, false
+	}
+
+	target := oid.RawBytes()
+	left := int(lo)
+
+	right := int(hi) - 1
+	for left <= right {
+		mid := left + (right-left)/2
+		start := mid * hashSize
+		end := start + hashSize
+
+		current := layer.chunkOIDLookup[start:end]
+
+		cmp := bytes.Compare(current, target)
+		switch {
+		case cmp == 0:
+			pos, err := intconv.IntToUint32(mid)
+			if err != nil {
+				return 0, false
+			}
+
+			return pos, true
+		case cmp < 0:
+			left = mid + 1
+		default:
+			right = mid - 1
+		}
+	}
+
+	return 0, false
+}
diff --git a/format/commitgraph/layer_open.go b/format/commitgraph/layer_open.go
new file mode 100644
index 00000000..857b3022
--- /dev/null
+++ b/format/commitgraph/layer_open.go
@@ -0,0 +1,80 @@
+package commitgraph
+
+import (
+	"os"
+	"syscall"
+
+	"codeberg.org/lindenii/furgit/internal/intconv"
+	"codeberg.org/lindenii/furgit/objectid"
+)
+
+func openLayer(root *os.Root, relPath string, algo objectid.Algorithm) (*layer, error) {
+	file, err := root.Open(relPath)
+	if err != nil {
+		return nil, err
+	}
+
+	info, err := file.Stat()
+	if err != nil {
+		_ = file.Close()
+
+		return nil, err
+	}
+
+	size := info.Size()
+	if size < int64(headerSize+fanoutSize+algo.Size()) {
+		_ = file.Close()
+
+		return nil, &ErrMalformed{Path: relPath, Reason: "file too short"}
+	}
+
+	mapLen, err := intconv.Int64ToUint64(size)
+	if err != nil {
+		_ = file.Close()
+
+		return nil, err
+	}
+
+	mapLenInt, err := intconv.Uint64ToInt(mapLen)
+	if err != nil {
+		_ = file.Close()
+
+		return nil, err
+	}
+
+	fd, err := intconv.UintptrToInt(file.Fd())
+	if err != nil {
+		_ = file.Close()
+
+		return nil, err
+	}
+
+	data, err := syscall.Mmap(fd, 0, mapLenInt, syscall.PROT_READ, syscall.MAP_PRIVATE)
+	if err != nil {
+		_ = file.Close()
+
+		return nil, err
+	}
+
+	out := &layer{
+		path: relPath,
+		file: file,
+		data: data,
+	}
+
+	parseErr := parseLayer(out, algo)
+	if parseErr != nil {
+		_ = out.close()
+
+		return nil, parseErr
+	}
+
+	verifyErr := verifyTrailerHash(out.data, algo, relPath)
+	if verifyErr != nil {
+		_ = out.close()
+
+		return nil, verifyErr
+	}
+
+	return out, nil
+}
diff --git a/format/commitgraph/layers.go b/format/commitgraph/layer_parse.go
index bdab6b79..d6d77b9e 100644
--- a/format/commitgraph/layers.go
+++ b/format/commitgraph/layer_parse.go
@@ -1,192 +1,13 @@
 package commitgraph
 
 import (
-	"bytes"
 	"encoding/binary"
-	"os"
-	"syscall"
 
 	"codeberg.org/lindenii/furgit/format/commitgraph/bloom"
 	"codeberg.org/lindenii/furgit/internal/intconv"
 	"codeberg.org/lindenii/furgit/objectid"
 )
 
-// LayerInfo describes one loaded commit-graph layer.
-type LayerInfo struct {
-	Path      string
-	BaseCount uint32
-	Commits   uint32
-}
-
-type layer struct {
-	path       string
-	file       *os.File
-	data       []byte
-	numCommits uint32
-	baseCount  uint32
-	globalFrom uint32
-
-	chunkOIDFanout    []byte
-	chunkOIDLookup    []byte
-	chunkCommit       []byte
-	chunkGeneration   []byte
-	chunkGenerationOv []byte
-	chunkExtraEdges   []byte
-	chunkBloomIndex   []byte
-	chunkBloomData    []byte
-	chunkBaseGraphs   []byte
-
-	bloomSettings *bloom.Settings
-}
-
-// Layers returns loaded layer metadata in native chain order.
-func (reader *Reader) Layers() []LayerInfo {
-	out := make([]LayerInfo, 0, len(reader.layers))
-	for i := range reader.layers {
-		layer := reader.layers[i]
-		out = append(out, LayerInfo{
-			Path:      layer.path,
-			BaseCount: layer.baseCount,
-			Commits:   layer.numCommits,
-		})
-	}
-
-	return out
-}
-
-func (reader *Reader) layerByPosition(pos Position) (*layer, error) {
-	graphIdx, err := intconv.Uint64ToInt(uint64(pos.Graph))
-	if err != nil {
-		return nil, err
-	}
-
-	if graphIdx < 0 || graphIdx >= len(reader.layers) {
-		return nil, &ErrPositionOutOfRange{Pos: pos}
-	}
-
-	layer := &reader.layers[graphIdx]
-	if pos.Index >= layer.numCommits {
-		return nil, &ErrPositionOutOfRange{Pos: pos}
-	}
-
-	return layer, nil
-}
-
-func layerLookup(layer *layer, oid objectid.ObjectID) (uint32, bool) {
-	hashSize := oid.Size()
-	first := int(oid.RawBytes()[0])
-
-	var lo uint32
-	if first > 0 {
-		lo = binary.BigEndian.Uint32(layer.chunkOIDFanout[(first-1)*4 : first*4])
-	}
-
-	hi := binary.BigEndian.Uint32(layer.chunkOIDFanout[first*4 : (first+1)*4])
-	if hi == 0 || lo >= hi {
-		return 0, false
-	}
-
-	target := oid.RawBytes()
-	left := int(lo)
-
-	right := int(hi) - 1
-	for left <= right {
-		mid := left + (right-left)/2
-		start := mid * hashSize
-		end := start + hashSize
-
-		current := layer.chunkOIDLookup[start:end]
-
-		cmp := bytes.Compare(current, target)
-		switch {
-		case cmp == 0:
-			pos, err := intconv.IntToUint32(mid)
-			if err != nil {
-				return 0, false
-			}
-
-			return pos, true
-		case cmp < 0:
-			left = mid + 1
-		default:
-			right = mid - 1
-		}
-	}
-
-	return 0, false
-}
-
-func openLayer(root *os.Root, relPath string, algo objectid.Algorithm) (*layer, error) {
-	file, err := root.Open(relPath)
-	if err != nil {
-		return nil, err
-	}
-
-	info, err := file.Stat()
-	if err != nil {
-		_ = file.Close()
-
-		return nil, err
-	}
-
-	size := info.Size()
-	if size < int64(headerSize+fanoutSize+algo.Size()) {
-		_ = file.Close()
-
-		return nil, &ErrMalformed{Path: relPath, Reason: "file too short"}
-	}
-
-	mapLen, err := intconv.Int64ToUint64(size)
-	if err != nil {
-		_ = file.Close()
-
-		return nil, err
-	}
-
-	mapLenInt, err := intconv.Uint64ToInt(mapLen)
-	if err != nil {
-		_ = file.Close()
-
-		return nil, err
-	}
-
-	fd, err := intconv.UintptrToInt(file.Fd())
-	if err != nil {
-		_ = file.Close()
-
-		return nil, err
-	}
-
-	data, err := syscall.Mmap(fd, 0, mapLenInt, syscall.PROT_READ, syscall.MAP_PRIVATE)
-	if err != nil {
-		_ = file.Close()
-
-		return nil, err
-	}
-
-	out := &layer{
-		path: relPath,
-		file: file,
-		data: data,
-	}
-
-	parseErr := parseLayer(out, algo)
-	if parseErr != nil {
-		_ = out.close()
-
-		return nil, parseErr
-	}
-
-	verifyErr := verifyTrailerHash(out.data, algo, relPath)
-	if verifyErr != nil {
-		_ = out.close()
-
-		return nil, verifyErr
-	}
-
-	return out, nil
-}
-
 func parseLayer(layer *layer, algo objectid.Algorithm) error { //nolint:maintidx
 	if len(layer.data) < headerSize {
 		return &ErrMalformed{Path: layer.path, Reason: "file too short"}
@@ -452,33 +273,3 @@ func parseLayer(layer *layer, algo objectid.Algorithm) error { //nolint:maintidx
 
 	return nil
 }
-
-func closeLayers(layers []layer) {
-	for i := len(layers) - 1; i >= 0; i-- {
-		_ = layers[i].close()
-	}
-}
-
-func (layer *layer) close() error {
-	var closeErr error
-
-	if layer.data != nil {
-		err := syscall.Munmap(layer.data)
-		if err != nil {
-			closeErr = err
-		}
-
-		layer.data = nil
-	}
-
-	if layer.file != nil {
-		err := layer.file.Close()
-		if err != nil && closeErr == nil {
-			closeErr = err
-		}
-
-		layer.file = nil
-	}
-
-	return closeErr
-}
diff --git a/format/commitgraph/layer_pos.go b/format/commitgraph/layer_pos.go
new file mode 100644
index 00000000..3b82c433
--- /dev/null
+++ b/format/commitgraph/layer_pos.go
@@ -0,0 +1,21 @@
+package commitgraph
+
+import "codeberg.org/lindenii/furgit/internal/intconv"
+
+func (reader *Reader) layerByPosition(pos Position) (*layer, error) {
+	graphIdx, err := intconv.Uint64ToInt(uint64(pos.Graph))
+	if err != nil {
+		return nil, err
+	}
+
+	if graphIdx < 0 || graphIdx >= len(reader.layers) {
+		return nil, &ErrPositionOutOfRange{Pos: pos}
+	}
+
+	layer := &reader.layers[graphIdx]
+	if pos.Index >= layer.numCommits {
+		return nil, &ErrPositionOutOfRange{Pos: pos}
+	}
+
+	return layer, nil
+}
diff --git a/format/commitgraph/layerinfo.go b/format/commitgraph/layerinfo.go
new file mode 100644
index 00000000..f5750368
--- /dev/null
+++ b/format/commitgraph/layerinfo.go
@@ -0,0 +1,23 @@
+package commitgraph
+
+// LayerInfo describes one loaded commit-graph layer.
+type LayerInfo struct {
+	Path      string
+	BaseCount uint32
+	Commits   uint32
+}
+
+// Layers returns loaded layer metadata in native chain order.
+func (reader *Reader) Layers() []LayerInfo {
+	out := make([]LayerInfo, 0, len(reader.layers))
+	for i := range reader.layers {
+		layer := reader.layers[i]
+		out = append(out, LayerInfo{
+			Path:      layer.path,
+			BaseCount: layer.baseCount,
+			Commits:   layer.numCommits,
+		})
+	}
+
+	return out
+}