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authorGibheer <gibheer+git@zero-knowledge.org>2024-09-05 19:38:25 +0200
committerGibheer <gibheer+git@zero-knowledge.org>2024-09-05 19:38:25 +0200
commit6ea4d2c82de80efc87708e5e182034b7c6c2019e (patch)
tree35c0856a929040216c82153ca62d43b27530a887 /vendor/github.com/jackc/pgx/v5/internal/iobufpool
parent6f64eeace1b66639b9380b44e88a8d54850a4306 (diff)
switch from github.com/lib/pq to github.com/jackc/pgx/v5HEAD20240905master
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')
-rw-r--r--vendor/github.com/jackc/pgx/v5/internal/iobufpool/iobufpool.go70
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
+}