runxiyu.tngl.sh
Fast implementation of Git in pure Go
internal/bufpool: Split files
+16
internal/bufpool/append.go
+16
internal/bufpool/append.go
···
1
+
package bufpool
2
+
3
+
// Append copies the provided bytes onto the end of the buffer, growing its
4
+
// capacity if required. If src is empty, the method does nothing.
5
+
//
6
+
// The receiver retains ownership of the data; the caller may reuse src freely.
7
+
func (buf *Buffer) Append(src []byte) {
8
+
if len(src) == 0 {
9
+
return
10
+
}
11
+
12
+
start := len(buf.buf)
13
+
buf.ensureCapacity(start + len(src))
14
+
buf.buf = buf.buf[:start+len(src)]
15
+
copy(buf.buf[start:], src)
16
+
}
+31
internal/bufpool/borrow.go
+31
internal/bufpool/borrow.go
···
1
+
package bufpool
2
+
3
+
// Borrow retrieves a Buffer suitable for storing up to capHint bytes.
4
+
// The returned Buffer may come from an internal sync.Pool.
5
+
//
6
+
// If capHint is smaller than DefaultBufferCap, it is automatically raised
7
+
// to DefaultBufferCap. If no pooled buffer has sufficient capacity, a new
8
+
// unpooled buffer is allocated.
9
+
//
10
+
// The caller must call Release() when finished using the returned Buffer.
11
+
func Borrow(capHint int) Buffer {
12
+
if capHint < DefaultBufferCap {
13
+
capHint = DefaultBufferCap
14
+
}
15
+
16
+
classIdx, classCap, pooled := classFor(capHint)
17
+
if !pooled {
18
+
newBuf := make([]byte, 0, capHint)
19
+
20
+
return Buffer{buf: newBuf, pool: unpooled}
21
+
}
22
+
//nolint:forcetypeassert
23
+
buf := bufferPools[classIdx].Get().(*[]byte)
24
+
if cap(*buf) < classCap {
25
+
*buf = make([]byte, 0, classCap)
26
+
}
27
+
28
+
slice := (*buf)[:0]
29
+
30
+
return Buffer{buf: slice, pool: poolIndex(classIdx)} //#nosec G115
31
+
}
+24
internal/bufpool/buffer.go
+24
internal/bufpool/buffer.go
···
1
+
package bufpool
2
+
3
+
// Buffer is a growable byte container that optionally participates in a
4
+
// memory pool. A Buffer may be obtained through Borrow() or constructed
5
+
// directly from owned data via FromOwned().
6
+
//
7
+
// A Buffer's underlying slice may grow as needed. When finished with a
8
+
// pooled buffer, the caller should invoke Release() to return it to the pool.
9
+
//
10
+
// Buffers must not be copied after first use; doing so can cause double-returns
11
+
// to the pool and data races.
12
+
//
13
+
// In general, pass Buffer around when used internally, and directly .Bytes() when
14
+
// returning output across our API boundary. It is neither necessary nor efficient
15
+
// to copy/append the .Bytes() to a newly-allocated slice; in cases where we do
16
+
// want the raw byte slice out of our API boundary, it is perfectly acceptable to
17
+
// simply not call Release().
18
+
//
19
+
//go:nocopy
20
+
type Buffer struct {
21
+
_ struct{} // for nocopy
22
+
buf []byte
23
+
pool poolIndex
24
+
}
-214
internal/bufpool/buffers.go
-214
internal/bufpool/buffers.go
···
1
-
// Package bufpool provides a lightweight byte-buffer type with optional
2
-
// pooling.
3
-
package bufpool
4
-
5
-
import "sync"
6
-
7
-
const (
8
-
// DefaultBufferCap is the minimum capacity a borrowed buffer will have.
9
-
// Borrow() will allocate or retrieve a buffer with at least this capacity.
10
-
DefaultBufferCap = 32 * 1024
11
-
12
-
// maxPooledBuffer defines the maximum capacity of a buffer that may be
13
-
// returned to the pool. Buffers larger than this will not be pooled to
14
-
// avoid unbounded memory usage.
15
-
maxPooledBuffer = 8 << 20
16
-
)
17
-
18
-
// Buffer is a growable byte container that optionally participates in a
19
-
// memory pool. A Buffer may be obtained through Borrow() or constructed
20
-
// directly from owned data via FromOwned().
21
-
//
22
-
// A Buffer's underlying slice may grow as needed. When finished with a
23
-
// pooled buffer, the caller should invoke Release() to return it to the pool.
24
-
//
25
-
// Buffers must not be copied after first use; doing so can cause double-returns
26
-
// to the pool and data races.
27
-
//
28
-
// In general, pass Buffer around when used internally, and directly .Bytes() when
29
-
// returning output across our API boundary. It is neither necessary nor efficient
30
-
// to copy/append the .Bytes() to a newly-allocated slice; in cases where we do
31
-
// want the raw byte slice out of our API boundary, it is perfectly acceptable to
32
-
// simply not call Release().
33
-
//
34
-
//go:nocopy
35
-
type Buffer struct {
36
-
_ struct{} // for nocopy
37
-
buf []byte
38
-
pool poolIndex
39
-
}
40
-
41
-
type poolIndex int8
42
-
43
-
const (
44
-
unpooled poolIndex = -1
45
-
)
46
-
47
-
var sizeClasses = [...]int{
48
-
DefaultBufferCap,
49
-
64 << 10,
50
-
128 << 10,
51
-
256 << 10,
52
-
512 << 10,
53
-
1 << 20,
54
-
2 << 20,
55
-
4 << 20,
56
-
maxPooledBuffer,
57
-
}
58
-
59
-
var bufferPools = func() []sync.Pool {
60
-
pools := make([]sync.Pool, len(sizeClasses))
61
-
for i, classCap := range sizeClasses {
62
-
capCopy := classCap
63
-
pools[i].New = func() any {
64
-
buf := make([]byte, 0, capCopy)
65
-
66
-
return &buf
67
-
}
68
-
}
69
-
70
-
return pools
71
-
}()
72
-
73
-
// Borrow retrieves a Buffer suitable for storing up to capHint bytes.
74
-
// The returned Buffer may come from an internal sync.Pool.
75
-
//
76
-
// If capHint is smaller than DefaultBufferCap, it is automatically raised
77
-
// to DefaultBufferCap. If no pooled buffer has sufficient capacity, a new
78
-
// unpooled buffer is allocated.
79
-
//
80
-
// The caller must call Release() when finished using the returned Buffer.
81
-
func Borrow(capHint int) Buffer {
82
-
if capHint < DefaultBufferCap {
83
-
capHint = DefaultBufferCap
84
-
}
85
-
86
-
classIdx, classCap, pooled := classFor(capHint)
87
-
if !pooled {
88
-
newBuf := make([]byte, 0, capHint)
89
-
90
-
return Buffer{buf: newBuf, pool: unpooled}
91
-
}
92
-
//nolint:forcetypeassert
93
-
buf := bufferPools[classIdx].Get().(*[]byte)
94
-
if cap(*buf) < classCap {
95
-
*buf = make([]byte, 0, classCap)
96
-
}
97
-
98
-
slice := (*buf)[:0]
99
-
100
-
return Buffer{buf: slice, pool: poolIndex(classIdx)} //#nosec G115
101
-
}
102
-
103
-
// FromOwned constructs a Buffer from a caller-owned byte slice. The resulting
104
-
// Buffer does not participate in pooling and will never be returned to the
105
-
// internal pool when released.
106
-
func FromOwned(buf []byte) Buffer {
107
-
return Buffer{buf: buf, pool: unpooled}
108
-
}
109
-
110
-
// Resize adjusts the length of the buffer to n bytes. If n exceeds the current
111
-
// capacity, the underlying storage is grown. If n is negative, it is treated
112
-
// as zero.
113
-
//
114
-
// The buffer's new contents beyond the previous length are undefined.
115
-
func (buf *Buffer) Resize(n int) {
116
-
if n < 0 {
117
-
n = 0
118
-
}
119
-
120
-
buf.ensureCapacity(n)
121
-
buf.buf = buf.buf[:n]
122
-
}
123
-
124
-
// Append copies the provided bytes onto the end of the buffer, growing its
125
-
// capacity if required. If src is empty, the method does nothing.
126
-
//
127
-
// The receiver retains ownership of the data; the caller may reuse src freely.
128
-
func (buf *Buffer) Append(src []byte) {
129
-
if len(src) == 0 {
130
-
return
131
-
}
132
-
133
-
start := len(buf.buf)
134
-
buf.ensureCapacity(start + len(src))
135
-
buf.buf = buf.buf[:start+len(src)]
136
-
copy(buf.buf[start:], src)
137
-
}
138
-
139
-
// Bytes returns the underlying byte slice that represents the current contents
140
-
// of the buffer. Modifying the returned slice modifies the Buffer itself.
141
-
func (buf *Buffer) Bytes() []byte {
142
-
return buf.buf
143
-
}
144
-
145
-
// Release returns the buffer to the global pool if it originated from the
146
-
// pool and its capacity is no larger than maxPooledBuffer. After release, the
147
-
// Buffer becomes invalid and should not be used further.
148
-
//
149
-
// Releasing a non-pooled buffer has no effect beyond clearing its internal
150
-
// storage.
151
-
func (buf *Buffer) Release() {
152
-
if buf.buf == nil {
153
-
return
154
-
}
155
-
156
-
buf.returnToPool()
157
-
buf.buf = nil
158
-
buf.pool = unpooled
159
-
}
160
-
161
-
// ensureCapacity grows the underlying buffer to accommodate the requested
162
-
// number of bytes. Growth doubles the capacity by default unless a larger
163
-
// expansion is needed. If the previous storage was pooled and not oversized,
164
-
// it is returned to the pool.
165
-
func (buf *Buffer) ensureCapacity(needed int) {
166
-
if cap(buf.buf) >= needed {
167
-
return
168
-
}
169
-
170
-
classIdx, classCap, pooled := classFor(needed)
171
-
172
-
var newBuf []byte
173
-
174
-
if pooled {
175
-
//nolint:forcetypeassert
176
-
raw := bufferPools[classIdx].Get().(*[]byte)
177
-
if cap(*raw) < classCap {
178
-
*raw = make([]byte, 0, classCap)
179
-
}
180
-
181
-
newBuf = (*raw)[:len(buf.buf)]
182
-
} else {
183
-
newBuf = make([]byte, len(buf.buf), classCap)
184
-
}
185
-
186
-
copy(newBuf, buf.buf)
187
-
buf.returnToPool()
188
-
189
-
buf.buf = newBuf
190
-
if pooled {
191
-
buf.pool = poolIndex(classIdx) //#nosec G115
192
-
} else {
193
-
buf.pool = unpooled
194
-
}
195
-
}
196
-
197
-
func classFor(size int) (idx, classCap int, ok bool) {
198
-
for i, class := range sizeClasses {
199
-
if size <= class {
200
-
return i, class, true
201
-
}
202
-
}
203
-
204
-
return -1, size, false
205
-
}
206
-
207
-
func (buf *Buffer) returnToPool() {
208
-
if buf.pool == unpooled {
209
-
return
210
-
}
211
-
212
-
tmp := buf.buf[:0]
213
-
bufferPools[int(buf.pool)].Put(&tmp)
214
-
}
+7
internal/bufpool/bytes.go
+7
internal/bufpool/bytes.go
+37
internal/bufpool/capacity.go
+37
internal/bufpool/capacity.go
···
1
+
package bufpool
2
+
3
+
// ensureCapacity grows the underlying buffer to accommodate the requested
4
+
// number of bytes. Growth doubles the capacity by default unless a larger
5
+
// expansion is needed. If the previous storage was pooled and not oversized,
6
+
// it is returned to the pool.
7
+
func (buf *Buffer) ensureCapacity(needed int) {
8
+
if cap(buf.buf) >= needed {
9
+
return
10
+
}
11
+
12
+
classIdx, classCap, pooled := classFor(needed)
13
+
14
+
var newBuf []byte
15
+
16
+
if pooled {
17
+
//nolint:forcetypeassert
18
+
raw := bufferPools[classIdx].Get().(*[]byte)
19
+
if cap(*raw) < classCap {
20
+
*raw = make([]byte, 0, classCap)
21
+
}
22
+
23
+
newBuf = (*raw)[:len(buf.buf)]
24
+
} else {
25
+
newBuf = make([]byte, len(buf.buf), classCap)
26
+
}
27
+
28
+
copy(newBuf, buf.buf)
29
+
buf.returnToPool()
30
+
31
+
buf.buf = newBuf
32
+
if pooled {
33
+
buf.pool = poolIndex(classIdx) //#nosec G115
34
+
} else {
35
+
buf.pool = unpooled
36
+
}
37
+
}
+23
internal/bufpool/class.go
+23
internal/bufpool/class.go
···
1
+
package bufpool
2
+
3
+
var sizeClasses = [...]int{
4
+
DefaultBufferCap,
5
+
64 << 10,
6
+
128 << 10,
7
+
256 << 10,
8
+
512 << 10,
9
+
1 << 20,
10
+
2 << 20,
11
+
4 << 20,
12
+
maxPooledBuffer,
13
+
}
14
+
15
+
func classFor(size int) (idx, classCap int, ok bool) {
16
+
for i, class := range sizeClasses {
17
+
if size <= class {
18
+
return i, class, true
19
+
}
20
+
}
21
+
22
+
return -1, size, false
23
+
}
+12
internal/bufpool/consts.go
+12
internal/bufpool/consts.go
···
1
+
package bufpool
2
+
3
+
const (
4
+
// DefaultBufferCap is the minimum capacity a borrowed buffer will have.
5
+
// Borrow() will allocate or retrieve a buffer with at least this capacity.
6
+
DefaultBufferCap = 32 * 1024
7
+
8
+
// maxPooledBuffer defines the maximum capacity of a buffer that may be
9
+
// returned to the pool. Buffers larger than this will not be pooled to
10
+
// avoid unbounded memory usage.
11
+
maxPooledBuffer = 8 << 20
12
+
)
+3
internal/bufpool/doc.go
+3
internal/bufpool/doc.go
+8
internal/bufpool/from_owned.go
+8
internal/bufpool/from_owned.go
···
1
+
package bufpool
2
+
3
+
// FromOwned constructs a Buffer from a caller-owned byte slice. The resulting
4
+
// Buffer does not participate in pooling and will never be returned to the
5
+
// internal pool when released.
6
+
func FromOwned(buf []byte) Buffer {
7
+
return Buffer{buf: buf, pool: unpooled}
8
+
}
+7
internal/bufpool/index.go
+7
internal/bufpool/index.go
+17
internal/bufpool/pool.go
+17
internal/bufpool/pool.go
···
1
+
package bufpool
2
+
3
+
import "sync"
4
+
5
+
var bufferPools = func() []sync.Pool {
6
+
pools := make([]sync.Pool, len(sizeClasses))
7
+
for i, classCap := range sizeClasses {
8
+
capCopy := classCap
9
+
pools[i].New = func() any {
10
+
buf := make([]byte, 0, capCopy)
11
+
12
+
return &buf
13
+
}
14
+
}
15
+
16
+
return pools
17
+
}()
+17
internal/bufpool/release.go
+17
internal/bufpool/release.go
···
1
+
package bufpool
2
+
3
+
// Release returns the buffer to the global pool if it originated from the
4
+
// pool and its capacity is no larger than maxPooledBuffer. After release, the
5
+
// Buffer becomes invalid and should not be used further.
6
+
//
7
+
// Releasing a non-pooled buffer has no effect beyond clearing its internal
8
+
// storage.
9
+
func (buf *Buffer) Release() {
10
+
if buf.buf == nil {
11
+
return
12
+
}
13
+
14
+
buf.returnToPool()
15
+
buf.buf = nil
16
+
buf.pool = unpooled
17
+
}
+15
internal/bufpool/resize.go
+15
internal/bufpool/resize.go
···
1
+
package bufpool
2
+
3
+
// Resize adjusts the length of the buffer to n bytes. If n exceeds the current
4
+
// capacity, the underlying storage is grown. If n is negative, it is treated
5
+
// as zero.
6
+
//
7
+
// The buffer's new contents beyond the previous length are undefined.
8
+
func (buf *Buffer) Resize(n int) {
9
+
if n < 0 {
10
+
n = 0
11
+
}
12
+
13
+
buf.ensureCapacity(n)
14
+
buf.buf = buf.buf[:n]
15
+
}