aboutsummaryrefslogtreecommitdiff
path: root/format/pack/ingest/idx_write.go
blob: 0523ac1d468ae7713518a6b8ad6c2fa19b74209e (about) (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
package ingest

import (
	"bytes"
	"encoding/binary"
	"fmt"
	"hash"
	"io"
	"slices"

	"codeberg.org/lindenii/furgit/internal/intconv"
	"codeberg.org/lindenii/furgit/internal/progress"
)

const (
	idxMagicV2   = 0xff744f63
	idxVersionV2 = 2
)

// writeIdx writes idx v2 for resolved records.
func writeIdx(state *ingestState) error {
	order := buildIdxOrder(state)

	hashImpl, err := state.algo.New()
	if err != nil {
		return err
	}

	write := func(src []byte) error {
		_, writeErr := state.idxFile.Write(src)
		if writeErr != nil {
			return writeErr
		}

		_, writeErr = hashImpl.Write(src)
		if writeErr != nil {
			return writeErr
		}

		return nil
	}

	var scratch [8]byte
	var fanout [256]uint32
	writeProgress(state, "writing index fanout...\r")

	for _, recordIdx := range order {
		idRaw := state.records[recordIdx].objectID.Bytes()
		fanout[idRaw[0]]++
	}

	binary.BigEndian.PutUint32(scratch[:4], idxMagicV2)
	binary.BigEndian.PutUint32(scratch[4:8], idxVersionV2)
	err = write(scratch[:8])
	if err != nil {
		return err
	}

	var cumulative uint32
	for i := range fanout {
		cumulative += fanout[i]
		binary.BigEndian.PutUint32(scratch[:4], cumulative)

		err := write(scratch[:4])
		if err != nil {
			return err
		}
	}
	writeProgress(state, "writing index fanout: done.\n")

	largeOffsetCount := 0
	for idx := range state.records {
		if state.records[idx].offset >= 0x80000000 {
			largeOffsetCount++
		}
	}

	oidMeter := progress.New(progress.Options{
		Writer: state.opts.Progress,
		Flush:  state.opts.ProgressFlush,
		Title:  "writing index object ids",
		Total:  uint64(len(order)),
	})
	var oidDone uint64

	for _, recordIdx := range order {
		idRaw := state.records[recordIdx].objectID.Bytes()

		err := write(idRaw)
		if err != nil {
			return err
		}

		oidDone++
		oidMeter.Set(oidDone, 0)
	}
	if oidDone > 0 {
		oidMeter.Stop("done")
	}

	crcMeter := progress.New(progress.Options{
		Writer: state.opts.Progress,
		Flush:  state.opts.ProgressFlush,
		Title:  "writing index crc32",
		Total:  uint64(len(order)),
	})
	var crcDone uint64

	for _, recordIdx := range order {
		binary.BigEndian.PutUint32(scratch[:4], state.records[recordIdx].crc32)

		err := write(scratch[:4])
		if err != nil {
			return err
		}

		crcDone++
		crcMeter.Set(crcDone, 0)
	}
	if crcDone > 0 {
		crcMeter.Stop("done")
	}

	largeOffsets := make([]uint64, 0)
	offsetMeter := progress.New(progress.Options{
		Writer: state.opts.Progress,
		Flush:  state.opts.ProgressFlush,
		Title:  "writing index offsets",
		Total:  uint64(len(order)),
	})
	var offsetDone uint64

	for _, recordIdx := range order {
		offset := state.records[recordIdx].offset
		if offset >= 0x80000000 {
			largeOffsetIdx, err := intconv.IntToUint32(len(largeOffsets))
			if err != nil {
				return err
			}

			word := 0x80000000 | largeOffsetIdx

			largeOffsets = append(largeOffsets, offset)

			binary.BigEndian.PutUint32(scratch[:4], word)
		} else {
			binary.BigEndian.PutUint32(scratch[:4], uint32(offset))
		}

		err := write(scratch[:4])
		if err != nil {
			return err
		}

		offsetDone++
		offsetMeter.Set(offsetDone, 0)
	}
	if offsetDone > 0 {
		offsetMeter.Stop("done")
	}

	largeOffsetMeter := progress.New(progress.Options{
		Writer: state.opts.Progress,
		Flush:  state.opts.ProgressFlush,
		Title:  "writing index large offsets",
		Total:  uint64(largeOffsetCount),
	})
	var largeOffsetDone uint64
	for _, off := range largeOffsets {
		binary.BigEndian.PutUint64(scratch[:8], off)

		err := write(scratch[:8])
		if err != nil {
			return err
		}

		largeOffsetDone++
		largeOffsetMeter.Set(largeOffsetDone, 0)
	}
	if largeOffsetDone > 0 {
		largeOffsetMeter.Stop("done")
	}

	writeProgress(state, "writing index trailer...\r")

	err = write(state.packHash.Bytes())
	if err != nil {
		return err
	}

	idxHash := hashImpl.Sum(nil)

	_, err = state.idxFile.Write(idxHash)
	if err != nil {
		return err
	}

	err = state.idxFile.Sync()
	if err != nil {
		return err
	}
	writeProgress(state, "writing index trailer: done.\n")

	return nil
}

// buildIdxOrder returns record indexes sorted by ObjectID.
func buildIdxOrder(state *ingestState) []int {
	out := make([]int, 0, len(state.records))
	for idx := range state.records {
		out = append(out, idx)
	}

	slices.SortFunc(out, func(a, b int) int {
		return bytes.Compare(state.records[a].objectID.Bytes(), state.records[b].objectID.Bytes())
	})

	return out
}

// verifyResolvedRecords checks that all records are fully resolved before index writing.
func verifyResolvedRecords(state *ingestState) error {
	for idx, record := range state.records {
		if !record.resolved {
			return fmt.Errorf("format/pack/ingest: unresolved record %d at offset %d", idx, record.offset)
		}
	}

	return nil
}

// writeAndHash writes src to dst and updates hash.
func writeAndHash(dst io.Writer, hashImpl hash.Hash, src []byte) error {
	_, err := dst.Write(src)
	if err != nil {
		return err
	}

	_, err = hashImpl.Write(src)
	if err != nil {
		return err
	}

	return nil
}