mirror of
https://github.com/seaweedfs/seaweedfs.git
synced 2026-10-06 14:31:57 +02:00
Chris Lu
4a1d65939f
* fix(filer): bound retained reader cache buffers by bytes * test(filer): keep in-flight downloads during cache trimming * feat(mem): expose pooled allocation capacity for byte reservations * fix(mount): share a configurable reader buffer budget across files * fix(filer): release failed prefetch slots and memory reservations * feat(mount): expose a soft Go runtime memory limit * docs(filer): restore shared-download rationale in startCaching The one-line comment replacing the original context.Background() explanation was too thin for readChunkAt to cross-reference shared resource semantics. Restore a concise note on why request cancellation must not abort a download shared by concurrent readers. * test(filer): loosen reader cache test deadlines to 5s Three tests used 1-second deadlines that can flake on CI under load: TestReaderCacheBudgetInFlight, TestReaderCacheEvictionDoesNotHoldCacheLock, and TestReaderCacheFailedPrefetchReleasesBudget. Increase to 5 seconds. * test(filer): cover re-read after reader cache eviction Add TestReaderCacheReReadAfterEviction: reads chunk 'a', reads chunk 'b' (evicting 'a' via budget pressure), then re-reads 'a' and asserts a fresh download returns correct data. Verifies the core correctness property that eviction never exposes missing or stale data to readers.
62 lines
1011 B
Go
62 lines
1011 B
Go
package mem
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import (
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"sync"
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)
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var pools []*sync.Pool
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const (
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min_size = 1024
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)
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func bitCount(size int) (count int) {
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for ; size > min_size; count++ {
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size = (size + 1) >> 1
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}
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return
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}
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func init() {
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// 1KB ~ 256MB
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pools = make([]*sync.Pool, bitCount(1024*1024*256))
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for i := 0; i < len(pools); i++ {
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slotSize := 1024 << i
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pools[i] = &sync.Pool{
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New: func() interface{} {
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buffer := make([]byte, slotSize)
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return &buffer
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},
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}
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}
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}
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func getSlotPool(size int) (*sync.Pool, bool) {
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index := bitCount(size)
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if index >= len(pools) {
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return nil, false
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}
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return pools[index], true
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}
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func AllocationSize(size int) int {
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if _, found := getSlotPool(size); found {
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return min_size << bitCount(size)
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}
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return size
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}
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func Allocate(size int) []byte {
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if pool, found := getSlotPool(size); found {
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slab := *pool.Get().(*[]byte)
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return slab[:size]
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}
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return make([]byte, size)
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}
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func Free(buf []byte) {
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if pool, found := getSlotPool(cap(buf)); found {
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pool.Put(&buf)
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}
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}
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