From 374ca2159407c6f3ec786bc19e25da44ded62fcf Mon Sep 17 00:00:00 2001 From: Runxi Yu Date: Fri, 6 Mar 2026 11:22:29 +0800 Subject: internal/bufpool: Split files --- internal/bufpool/buffers.go | 214 -------------------------------------------- 1 file changed, 214 deletions(-) delete mode 100644 internal/bufpool/buffers.go (limited to 'internal/bufpool/buffers.go') diff --git a/internal/bufpool/buffers.go b/internal/bufpool/buffers.go deleted file mode 100644 index 91e30a31..00000000 --- a/internal/bufpool/buffers.go +++ /dev/null @@ -1,214 +0,0 @@ -// Package bufpool provides a lightweight byte-buffer type with optional -// pooling. -package bufpool - -import "sync" - -const ( - // DefaultBufferCap is the minimum capacity a borrowed buffer will have. - // Borrow() will allocate or retrieve a buffer with at least this capacity. - DefaultBufferCap = 32 * 1024 - - // maxPooledBuffer defines the maximum capacity of a buffer that may be - // returned to the pool. Buffers larger than this will not be pooled to - // avoid unbounded memory usage. - maxPooledBuffer = 8 << 20 -) - -// Buffer is a growable byte container that optionally participates in a -// memory pool. A Buffer may be obtained through Borrow() or constructed -// directly from owned data via FromOwned(). -// -// A Buffer's underlying slice may grow as needed. When finished with a -// pooled buffer, the caller should invoke Release() to return it to the pool. -// -// Buffers must not be copied after first use; doing so can cause double-returns -// to the pool and data races. -// -// In general, pass Buffer around when used internally, and directly .Bytes() when -// returning output across our API boundary. It is neither necessary nor efficient -// to copy/append the .Bytes() to a newly-allocated slice; in cases where we do -// want the raw byte slice out of our API boundary, it is perfectly acceptable to -// simply not call Release(). -// -//go:nocopy -type Buffer struct { - _ struct{} // for nocopy - buf []byte - pool poolIndex -} - -type poolIndex int8 - -const ( - unpooled poolIndex = -1 -) - -var sizeClasses = [...]int{ - DefaultBufferCap, - 64 << 10, - 128 << 10, - 256 << 10, - 512 << 10, - 1 << 20, - 2 << 20, - 4 << 20, - maxPooledBuffer, -} - -var bufferPools = func() []sync.Pool { - pools := make([]sync.Pool, len(sizeClasses)) - for i, classCap := range sizeClasses { - capCopy := classCap - pools[i].New = func() any { - buf := make([]byte, 0, capCopy) - - return &buf - } - } - - return pools -}() - -// Borrow retrieves a Buffer suitable for storing up to capHint bytes. -// The returned Buffer may come from an internal sync.Pool. -// -// If capHint is smaller than DefaultBufferCap, it is automatically raised -// to DefaultBufferCap. If no pooled buffer has sufficient capacity, a new -// unpooled buffer is allocated. -// -// The caller must call Release() when finished using the returned Buffer. -func Borrow(capHint int) Buffer { - if capHint < DefaultBufferCap { - capHint = DefaultBufferCap - } - - classIdx, classCap, pooled := classFor(capHint) - if !pooled { - newBuf := make([]byte, 0, capHint) - - return Buffer{buf: newBuf, pool: unpooled} - } - //nolint:forcetypeassert - buf := bufferPools[classIdx].Get().(*[]byte) - if cap(*buf) < classCap { - *buf = make([]byte, 0, classCap) - } - - slice := (*buf)[:0] - - return Buffer{buf: slice, pool: poolIndex(classIdx)} //#nosec G115 -} - -// FromOwned constructs a Buffer from a caller-owned byte slice. The resulting -// Buffer does not participate in pooling and will never be returned to the -// internal pool when released. -func FromOwned(buf []byte) Buffer { - return Buffer{buf: buf, pool: unpooled} -} - -// Resize adjusts the length of the buffer to n bytes. If n exceeds the current -// capacity, the underlying storage is grown. If n is negative, it is treated -// as zero. -// -// The buffer's new contents beyond the previous length are undefined. -func (buf *Buffer) Resize(n int) { - if n < 0 { - n = 0 - } - - buf.ensureCapacity(n) - buf.buf = buf.buf[:n] -} - -// Append copies the provided bytes onto the end of the buffer, growing its -// capacity if required. If src is empty, the method does nothing. -// -// The receiver retains ownership of the data; the caller may reuse src freely. -func (buf *Buffer) Append(src []byte) { - if len(src) == 0 { - return - } - - start := len(buf.buf) - buf.ensureCapacity(start + len(src)) - buf.buf = buf.buf[:start+len(src)] - copy(buf.buf[start:], src) -} - -// Bytes returns the underlying byte slice that represents the current contents -// of the buffer. Modifying the returned slice modifies the Buffer itself. -func (buf *Buffer) Bytes() []byte { - return buf.buf -} - -// Release returns the buffer to the global pool if it originated from the -// pool and its capacity is no larger than maxPooledBuffer. After release, the -// Buffer becomes invalid and should not be used further. -// -// Releasing a non-pooled buffer has no effect beyond clearing its internal -// storage. -func (buf *Buffer) Release() { - if buf.buf == nil { - return - } - - buf.returnToPool() - buf.buf = nil - buf.pool = unpooled -} - -// ensureCapacity grows the underlying buffer to accommodate the requested -// number of bytes. Growth doubles the capacity by default unless a larger -// expansion is needed. If the previous storage was pooled and not oversized, -// it is returned to the pool. -func (buf *Buffer) ensureCapacity(needed int) { - if cap(buf.buf) >= needed { - return - } - - classIdx, classCap, pooled := classFor(needed) - - var newBuf []byte - - if pooled { - //nolint:forcetypeassert - raw := bufferPools[classIdx].Get().(*[]byte) - if cap(*raw) < classCap { - *raw = make([]byte, 0, classCap) - } - - newBuf = (*raw)[:len(buf.buf)] - } else { - newBuf = make([]byte, len(buf.buf), classCap) - } - - copy(newBuf, buf.buf) - buf.returnToPool() - - buf.buf = newBuf - if pooled { - buf.pool = poolIndex(classIdx) //#nosec G115 - } else { - buf.pool = unpooled - } -} - -func classFor(size int) (idx, classCap int, ok bool) { - for i, class := range sizeClasses { - if size <= class { - return i, class, true - } - } - - return -1, size, false -} - -func (buf *Buffer) returnToPool() { - if buf.pool == unpooled { - return - } - - tmp := buf.buf[:0] - bufferPools[int(buf.pool)].Put(&tmp) -} -- cgit v1.3.1-10-gc9f91