view mercurial/compat.h @ 42462:bc4373babd04

revlog: add the option to track the expected compression upper bound

There are various optimization we can do if we can estimate the size of delta
before actually spending CPU compressing them. So we add a attributed dedicated
to tracking that.

We only use it on Manifest because (1) it structure is quite stable across all
Mercurial repository so its compression ratio is fairly universal. This is the
revlog with most extreme delta (cf the sparse-revlog optimization).

This will be put to use in later changesets.

Right now the compression upper bound is set to 10. This is a fairly
conservative value (observed value is more around 3), but I prefer to be safe
while introducing the optimization principles. We can tune the optimization
threshold later.

#ifndef _HG_COMPAT_H_
#define _HG_COMPAT_H_

#ifdef _WIN32
#ifdef _MSC_VER
#if _MSC_VER < 1900
/* msvc 6.0 has problems */
#define inline __inline
#if defined(_WIN64)
typedef __int64 ssize_t;
typedef unsigned __int64 uintptr_t;
#else
typedef int ssize_t;
typedef unsigned int uintptr_t;
#endif
typedef signed char int8_t;
typedef short int16_t;
typedef long int32_t;
typedef __int64 int64_t;
typedef unsigned char uint8_t;
typedef unsigned short uint16_t;
typedef unsigned long uint32_t;
typedef unsigned __int64 uint64_t;
#else
/* VC++ 14 */
#include <stdint.h>

#if defined(_WIN64)
typedef __int64 ssize_t;
#else
typedef int ssize_t;
#endif
#endif /* _MSC_VER < 1900 */

#else
/* not msvc */
#include <stdint.h>
#endif
#else
/* not windows */
#include <sys/types.h>
#if defined __BEOS__ && !defined __HAIKU__
#include <ByteOrder.h>
#else
#include <arpa/inet.h>
#endif
#include <inttypes.h>
#endif

#if defined __hpux || defined __SUNPRO_C || defined _AIX
#define inline
#endif

#ifdef __linux
#define inline __inline
#endif

#endif