haiku/headers/private/kernel/fs/KPath.h
Augustin Cavalier 42e3c6f978 KPath: Use an object_cache for the path buffers in the normal case.
This was (following the packagefs changes) the number-one (by call
count) consumer of malloc() during the boot -- 52866 calls, and 100%
of them either 1024 or 1025 bytes!

Virtually all of these are ephemeral (indeed, the object_cache
stats after a boot with this patch shows there is only a single slab
of 64 buffers allocated, and most of them unused), so this is
probably a significant performance boost.

Change-Id: I659f5707510cbfeafa735d35eea7b92732ead666
2019-07-11 22:52:10 -04:00

94 lines
2.1 KiB
C++

/*
* Copyright 2004-2008, Ingo Weinhold, ingo_weinhold@gmx.de.
* Copyright 2008-2017, Axel Dörfler, axeld@pinc-software.de.
* Distributed under the terms of the MIT License.
*/
#ifndef _K_PATH_H
#define _K_PATH_H
#include <KernelExport.h>
namespace BPrivate {
namespace DiskDevice {
class KPath {
public:
enum {
DEFAULT = 0,
NORMALIZE = 0x01,
TRAVERSE_LEAF_LINK = 0x02,
LAZY_ALLOC = 0x04
};
public:
KPath(size_t bufferSize = B_PATH_NAME_LENGTH + 1);
KPath(const char* path, int32 flags = DEFAULT,
size_t bufferSize = B_PATH_NAME_LENGTH + 1);
KPath(const KPath& other);
~KPath();
status_t SetTo(const char* path, int32 flags = DEFAULT,
size_t bufferSize = B_PATH_NAME_LENGTH + 1);
void Adopt(KPath& other);
status_t InitCheck() const;
status_t SetPath(const char* path,
int32 flags = DEFAULT);
const char* Path() const;
size_t Length() const
{ return fPathLength; }
size_t BufferSize() const
{ return fBufferSize; }
char* LockBuffer(bool force = false);
void UnlockBuffer();
char* DetachBuffer();
const char* Leaf() const;
status_t ReplaceLeaf(const char* newLeaf);
bool RemoveLeaf();
// returns false, if nothing could be removed anymore
status_t Append(const char* toAppend,
bool isComponent = true);
status_t Normalize(bool traverseLeafLink);
KPath& operator=(const KPath& other);
KPath& operator=(const char* path);
bool operator==(const KPath& other) const;
bool operator==(const char* path) const;
bool operator!=(const KPath& other) const;
bool operator!=(const char* path) const;
private:
status_t _AllocateBuffer();
void _FreeBuffer();
status_t _Normalize(const char* path,
bool traverseLeafLink);
void _ChopTrailingSlashes();
private:
char* fBuffer;
size_t fBufferSize;
size_t fPathLength;
bool fLocked;
bool fLazy;
bool fFailed;
bool fIsNull;
};
} // namespace DiskDevice
} // namespace BPrivate
using BPrivate::DiskDevice::KPath;
#endif /* _K_PATH_H */