view mercurial/bitmanipulation.h @ 39996:dbcb466d0065

localrepo: define storage backend in creation options (API)

We add an experimental config option to define the storage backend
for new repositories. By default, it uses "revlogv1," which maps to
the current and only modern supported repository format.

We add a "backend" creation option to control which backend to
use. It defaults to using the value from the config option.

newreporequirements() will now barf if it sees a "backend" value
that isn't "revlogv1." This forces extensions to monkeypatch the
function to handle requirements derivation for custom backends.

In order for this to "just work," we factored out obtaining the
default creation options into its own function and made callers
of newreporequirements() responsible for passing in valid data.
Without this, direct callers of newreporequirements() wouldn't
get the proper results.

Differential Revision: https://phab.mercurial-scm.org/D4791

#ifndef _HG_BITMANIPULATION_H_
#define _HG_BITMANIPULATION_H_

#include <string.h>

#include "compat.h"

static inline uint32_t getbe32(const char *c)
{
	const unsigned char *d = (const unsigned char *)c;

	return ((((uint32_t)d[0]) << 24) | (((uint32_t)d[1]) << 16) |
	        (((uint32_t)d[2]) << 8) | (d[3]));
}

static inline int16_t getbeint16(const char *c)
{
	const unsigned char *d = (const unsigned char *)c;

	return ((d[0] << 8) | (d[1]));
}

static inline uint16_t getbeuint16(const char *c)
{
	const unsigned char *d = (const unsigned char *)c;

	return ((d[0] << 8) | (d[1]));
}

static inline void putbe32(uint32_t x, char *c)
{
	c[0] = (x >> 24) & 0xff;
	c[1] = (x >> 16) & 0xff;
	c[2] = (x >> 8) & 0xff;
	c[3] = (x)&0xff;
}

static inline double getbefloat64(const char *c)
{
	const unsigned char *d = (const unsigned char *)c;
	double ret;
	int i;
	uint64_t t = 0;
	for (i = 0; i < 8; i++) {
		t = (t << 8) + d[i];
	}
	memcpy(&ret, &t, sizeof(t));
	return ret;
}

#endif