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authorLibravatar tobi <31960611+tsmethurst@users.noreply.github.com>2024-09-16 11:06:00 +0200
committerLibravatar GitHub <noreply@github.com>2024-09-16 09:06:00 +0000
commitb2572b9e074ebbce8bcf1b9979d4d8ea066650d6 (patch)
tree0c2a08ed63b582676ce7661252a6917db751c62a /vendor/google.golang.org/grpc/mem/buffer_slice.go
parent[chore]: Bump golang.org/x/net from 0.28.0 to 0.29.0 (#3303) (diff)
downloadgotosocial-b2572b9e074ebbce8bcf1b9979d4d8ea066650d6.tar.xz
[chore] Bump otel deps -> v1.30.0/v0.52.0 (#3307)
Diffstat (limited to 'vendor/google.golang.org/grpc/mem/buffer_slice.go')
-rw-r--r--vendor/google.golang.org/grpc/mem/buffer_slice.go224
1 files changed, 224 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/mem/buffer_slice.go b/vendor/google.golang.org/grpc/mem/buffer_slice.go
new file mode 100644
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+++ b/vendor/google.golang.org/grpc/mem/buffer_slice.go
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+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package mem
+
+import (
+ "compress/flate"
+ "io"
+)
+
+// BufferSlice offers a means to represent data that spans one or more Buffer
+// instances. A BufferSlice is meant to be immutable after creation, and methods
+// like Ref create and return copies of the slice. This is why all methods have
+// value receivers rather than pointer receivers.
+//
+// Note that any of the methods that read the underlying buffers such as Ref,
+// Len or CopyTo etc., will panic if any underlying buffers have already been
+// freed. It is recommended to not directly interact with any of the underlying
+// buffers directly, rather such interactions should be mediated through the
+// various methods on this type.
+//
+// By convention, any APIs that return (mem.BufferSlice, error) should reduce
+// the burden on the caller by never returning a mem.BufferSlice that needs to
+// be freed if the error is non-nil, unless explicitly stated.
+type BufferSlice []Buffer
+
+// Len returns the sum of the length of all the Buffers in this slice.
+//
+// # Warning
+//
+// Invoking the built-in len on a BufferSlice will return the number of buffers
+// in the slice, and *not* the value returned by this function.
+func (s BufferSlice) Len() int {
+ var length int
+ for _, b := range s {
+ length += b.Len()
+ }
+ return length
+}
+
+// Ref invokes Ref on each buffer in the slice.
+func (s BufferSlice) Ref() {
+ for _, b := range s {
+ b.Ref()
+ }
+}
+
+// Free invokes Buffer.Free() on each Buffer in the slice.
+func (s BufferSlice) Free() {
+ for _, b := range s {
+ b.Free()
+ }
+}
+
+// CopyTo copies each of the underlying Buffer's data into the given buffer,
+// returning the number of bytes copied. Has the same semantics as the copy
+// builtin in that it will copy as many bytes as it can, stopping when either dst
+// is full or s runs out of data, returning the minimum of s.Len() and len(dst).
+func (s BufferSlice) CopyTo(dst []byte) int {
+ off := 0
+ for _, b := range s {
+ off += copy(dst[off:], b.ReadOnlyData())
+ }
+ return off
+}
+
+// Materialize concatenates all the underlying Buffer's data into a single
+// contiguous buffer using CopyTo.
+func (s BufferSlice) Materialize() []byte {
+ l := s.Len()
+ if l == 0 {
+ return nil
+ }
+ out := make([]byte, l)
+ s.CopyTo(out)
+ return out
+}
+
+// MaterializeToBuffer functions like Materialize except that it writes the data
+// to a single Buffer pulled from the given BufferPool. As a special case, if the
+// input BufferSlice only actually has one Buffer, this function has nothing to
+// do and simply returns said Buffer.
+func (s BufferSlice) MaterializeToBuffer(pool BufferPool) Buffer {
+ if len(s) == 1 {
+ s[0].Ref()
+ return s[0]
+ }
+ sLen := s.Len()
+ if sLen == 0 {
+ return emptyBuffer{}
+ }
+ buf := pool.Get(sLen)
+ s.CopyTo(*buf)
+ return NewBuffer(buf, pool)
+}
+
+// Reader returns a new Reader for the input slice after taking references to
+// each underlying buffer.
+func (s BufferSlice) Reader() Reader {
+ s.Ref()
+ return &sliceReader{
+ data: s,
+ len: s.Len(),
+ }
+}
+
+// Reader exposes a BufferSlice's data as an io.Reader, allowing it to interface
+// with other parts systems. It also provides an additional convenience method
+// Remaining(), which returns the number of unread bytes remaining in the slice.
+// Buffers will be freed as they are read.
+type Reader interface {
+ flate.Reader
+ // Close frees the underlying BufferSlice and never returns an error. Subsequent
+ // calls to Read will return (0, io.EOF).
+ Close() error
+ // Remaining returns the number of unread bytes remaining in the slice.
+ Remaining() int
+}
+
+type sliceReader struct {
+ data BufferSlice
+ len int
+ // The index into data[0].ReadOnlyData().
+ bufferIdx int
+}
+
+func (r *sliceReader) Remaining() int {
+ return r.len
+}
+
+func (r *sliceReader) Close() error {
+ r.data.Free()
+ r.data = nil
+ r.len = 0
+ return nil
+}
+
+func (r *sliceReader) freeFirstBufferIfEmpty() bool {
+ if len(r.data) == 0 || r.bufferIdx != len(r.data[0].ReadOnlyData()) {
+ return false
+ }
+
+ r.data[0].Free()
+ r.data = r.data[1:]
+ r.bufferIdx = 0
+ return true
+}
+
+func (r *sliceReader) Read(buf []byte) (n int, _ error) {
+ if r.len == 0 {
+ return 0, io.EOF
+ }
+
+ for len(buf) != 0 && r.len != 0 {
+ // Copy as much as possible from the first Buffer in the slice into the
+ // given byte slice.
+ data := r.data[0].ReadOnlyData()
+ copied := copy(buf, data[r.bufferIdx:])
+ r.len -= copied // Reduce len by the number of bytes copied.
+ r.bufferIdx += copied // Increment the buffer index.
+ n += copied // Increment the total number of bytes read.
+ buf = buf[copied:] // Shrink the given byte slice.
+
+ // If we have copied all the data from the first Buffer, free it and advance to
+ // the next in the slice.
+ r.freeFirstBufferIfEmpty()
+ }
+
+ return n, nil
+}
+
+func (r *sliceReader) ReadByte() (byte, error) {
+ if r.len == 0 {
+ return 0, io.EOF
+ }
+
+ // There may be any number of empty buffers in the slice, clear them all until a
+ // non-empty buffer is reached. This is guaranteed to exit since r.len is not 0.
+ for r.freeFirstBufferIfEmpty() {
+ }
+
+ b := r.data[0].ReadOnlyData()[r.bufferIdx]
+ r.len--
+ r.bufferIdx++
+ // Free the first buffer in the slice if the last byte was read
+ r.freeFirstBufferIfEmpty()
+ return b, nil
+}
+
+var _ io.Writer = (*writer)(nil)
+
+type writer struct {
+ buffers *BufferSlice
+ pool BufferPool
+}
+
+func (w *writer) Write(p []byte) (n int, err error) {
+ b := Copy(p, w.pool)
+ *w.buffers = append(*w.buffers, b)
+ return b.Len(), nil
+}
+
+// NewWriter wraps the given BufferSlice and BufferPool to implement the
+// io.Writer interface. Every call to Write copies the contents of the given
+// buffer into a new Buffer pulled from the given pool and the Buffer is added to
+// the given BufferSlice.
+func NewWriter(buffers *BufferSlice, pool BufferPool) io.Writer {
+ return &writer{buffers: buffers, pool: pool}
+}