diff options
Diffstat (limited to 'vendor/github.com/jackc/puddle/v2/log.go')
-rw-r--r-- | vendor/github.com/jackc/puddle/v2/log.go | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/vendor/github.com/jackc/puddle/v2/log.go b/vendor/github.com/jackc/puddle/v2/log.go new file mode 100644 index 0000000..b21b946 --- /dev/null +++ b/vendor/github.com/jackc/puddle/v2/log.go @@ -0,0 +1,32 @@ +package puddle + +import "unsafe" + +type ints interface { + int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 +} + +// log2Int returns log2 of an integer. This function panics if val < 0. For val +// == 0, returns 0. +func log2Int[T ints](val T) uint8 { + if val <= 0 { + panic("log2 of non-positive number does not exist") + } + + return log2IntRange(val, 0, uint8(8*unsafe.Sizeof(val))) +} + +func log2IntRange[T ints](val T, begin, end uint8) uint8 { + length := end - begin + if length == 1 { + return begin + } + + delim := begin + length/2 + mask := T(1) << delim + if mask > val { + return log2IntRange(val, begin, delim) + } else { + return log2IntRange(val, delim, end) + } +} |