diff options
author | Gibheer <gibheer+git@zero-knowledge.org> | 2024-09-05 19:38:25 +0200 |
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committer | Gibheer <gibheer+git@zero-knowledge.org> | 2024-09-05 19:38:25 +0200 |
commit | 6ea4d2c82de80efc87708e5e182034b7c6c2019e (patch) | |
tree | 35c0856a929040216c82153ca62d43b27530a887 /vendor/github.com/jackc/pgx/v5/internal/iobufpool/iobufpool.go | |
parent | 6f64eeace1b66639b9380b44e88a8d54850a4306 (diff) |
lib/pq is out of maintenance for some time now, so switch to the newer
more active library. Looks like it finally stabilized after a long time.
Diffstat (limited to 'vendor/github.com/jackc/pgx/v5/internal/iobufpool/iobufpool.go')
-rw-r--r-- | vendor/github.com/jackc/pgx/v5/internal/iobufpool/iobufpool.go | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/vendor/github.com/jackc/pgx/v5/internal/iobufpool/iobufpool.go b/vendor/github.com/jackc/pgx/v5/internal/iobufpool/iobufpool.go new file mode 100644 index 0000000..89e0c22 --- /dev/null +++ b/vendor/github.com/jackc/pgx/v5/internal/iobufpool/iobufpool.go @@ -0,0 +1,70 @@ +// Package iobufpool implements a global segregated-fit pool of buffers for IO. +// +// It uses *[]byte instead of []byte to avoid the sync.Pool allocation with Put. Unfortunately, using a pointer to avoid +// an allocation is purposely not documented. https://github.com/golang/go/issues/16323 +package iobufpool + +import "sync" + +const minPoolExpOf2 = 8 + +var pools [18]*sync.Pool + +func init() { + for i := range pools { + bufLen := 1 << (minPoolExpOf2 + i) + pools[i] = &sync.Pool{ + New: func() any { + buf := make([]byte, bufLen) + return &buf + }, + } + } +} + +// Get gets a []byte of len size with cap <= size*2. +func Get(size int) *[]byte { + i := getPoolIdx(size) + if i >= len(pools) { + buf := make([]byte, size) + return &buf + } + + ptrBuf := (pools[i].Get().(*[]byte)) + *ptrBuf = (*ptrBuf)[:size] + + return ptrBuf +} + +func getPoolIdx(size int) int { + size-- + size >>= minPoolExpOf2 + i := 0 + for size > 0 { + size >>= 1 + i++ + } + + return i +} + +// Put returns buf to the pool. +func Put(buf *[]byte) { + i := putPoolIdx(cap(*buf)) + if i < 0 { + return + } + + pools[i].Put(buf) +} + +func putPoolIdx(size int) int { + minPoolSize := 1 << minPoolExpOf2 + for i := range pools { + if size == minPoolSize<<i { + return i + } + } + + return -1 +} |