rebase: use one dirstateguard for when using rebase.singletransaction
This was previously landed as 2519994d25ca but backed out in b63351f6a2 because
it broke hooks mid-rebase and caused conflict resolution data loss in the event
of unexpected exceptions. This new version adds the behavior back but behind a
config flag, since the performance improvement is notable in large repositories.
The old commit message was:
Recently we switched rebases to run the entire rebase inside a single
transaction, which dramatically improved the speed of rebases in repos with
large working copies. Let's also move the dirstate into a single dirstateguard
to get the same benefits. This let's us avoid serializing the dirstate after
each commit.
In a large repo, rebasing 27 commits is sped up by about 20%.
I believe the test changes are because us touching the dirstate gave the
transaction something to actually rollback.
(grafted from 9e3dc3a1638b9754b58a0cb26aaa75d868058109)
(grafted from 7d38b41d2266d9a02a15c64229fae0da5738dcec)
Differential Revision: https://phab.mercurial-scm.org/D135
#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 ((d[0] << 24) |
(d[1] << 16) |
(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