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git/environment.c
David Kastrup 4874f544f1 Bump core.deltaBaseCacheLimit to 96m
The default of 16m causes serious thrashing for large delta chains
combined with large files.

Here are some benchmarks (pu variant of git blame):

time git blame -C src/xdisp.c >/dev/null

for a repository of Emacs repacked with git gc --aggressive (v1.9,
resulting in a window size of 250) located on an SSD drive.  The file in
question has about 30000 lines, 1Mb of size, and a history with about
2500 commits.

    16m (previous default):
    real	3m33.936s
    user	2m15.396s
    sys	1m17.352s

    32m:
    real	3m1.319s
    user	2m8.660s
    sys	0m51.904s

    64m:
    real	2m20.636s
    user	1m55.780s
    sys	0m23.964s

    96m:
    real	2m5.668s
    user	1m50.784s
    sys	0m14.288s

    128m:
    real	2m4.337s
    user	1m50.764s
    sys	0m12.832s

    192m:
    real	2m3.567s
    user	1m49.508s
    sys	0m13.312s

Signed-off-by: David Kastrup <dak@gnu.org>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-05-06 15:32:21 -07:00

287 lines
7.5 KiB
C

/*
* We put all the git config variables in this same object
* file, so that programs can link against the config parser
* without having to link against all the rest of git.
*
* In particular, no need to bring in libz etc unless needed,
* even if you might want to know where the git directory etc
* are.
*/
#include "cache.h"
#include "refs.h"
#include "fmt-merge-msg.h"
#include "commit.h"
int trust_executable_bit = 1;
int trust_ctime = 1;
int check_stat = 1;
int has_symlinks = 1;
int minimum_abbrev = 4, default_abbrev = 7;
int ignore_case;
int assume_unchanged;
int prefer_symlink_refs;
int is_bare_repository_cfg = -1; /* unspecified */
int log_all_ref_updates = -1; /* unspecified */
int warn_ambiguous_refs = 1;
int warn_on_object_refname_ambiguity = 1;
int repository_format_version;
const char *git_commit_encoding;
const char *git_log_output_encoding;
int shared_repository = PERM_UMASK;
const char *apply_default_whitespace;
const char *apply_default_ignorewhitespace;
const char *git_attributes_file;
int zlib_compression_level = Z_BEST_SPEED;
int core_compression_level;
int core_compression_seen;
int fsync_object_files;
size_t packed_git_window_size = DEFAULT_PACKED_GIT_WINDOW_SIZE;
size_t packed_git_limit = DEFAULT_PACKED_GIT_LIMIT;
size_t delta_base_cache_limit = 96 * 1024 * 1024;
unsigned long big_file_threshold = 512 * 1024 * 1024;
const char *pager_program;
int pager_use_color = 1;
const char *editor_program;
const char *askpass_program;
const char *excludes_file;
enum auto_crlf auto_crlf = AUTO_CRLF_FALSE;
int check_replace_refs = 1;
enum eol core_eol = EOL_UNSET;
enum safe_crlf safe_crlf = SAFE_CRLF_WARN;
unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
enum branch_track git_branch_track = BRANCH_TRACK_REMOTE;
enum rebase_setup_type autorebase = AUTOREBASE_NEVER;
enum push_default_type push_default = PUSH_DEFAULT_UNSPECIFIED;
#ifndef OBJECT_CREATION_MODE
#define OBJECT_CREATION_MODE OBJECT_CREATION_USES_HARDLINKS
#endif
enum object_creation_mode object_creation_mode = OBJECT_CREATION_MODE;
char *notes_ref_name;
int grafts_replace_parents = 1;
int core_apply_sparse_checkout;
int merge_log_config = -1;
int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */
struct startup_info *startup_info;
unsigned long pack_size_limit_cfg;
/*
* The character that begins a commented line in user-editable file
* that is subject to stripspace.
*/
char comment_line_char = '#';
/* Parallel index stat data preload? */
int core_preload_index = 0;
/* This is set by setup_git_dir_gently() and/or git_default_config() */
char *git_work_tree_cfg;
static char *work_tree;
static const char *namespace;
static size_t namespace_len;
static const char *git_dir;
static char *git_object_dir, *git_index_file, *git_graft_file;
/*
* Repository-local GIT_* environment variables; see cache.h for details.
*/
const char * const local_repo_env[] = {
ALTERNATE_DB_ENVIRONMENT,
CONFIG_ENVIRONMENT,
CONFIG_DATA_ENVIRONMENT,
DB_ENVIRONMENT,
GIT_DIR_ENVIRONMENT,
GIT_WORK_TREE_ENVIRONMENT,
GIT_IMPLICIT_WORK_TREE_ENVIRONMENT,
GRAFT_ENVIRONMENT,
INDEX_ENVIRONMENT,
NO_REPLACE_OBJECTS_ENVIRONMENT,
GIT_PREFIX_ENVIRONMENT,
GIT_SHALLOW_FILE_ENVIRONMENT,
NULL
};
static char *expand_namespace(const char *raw_namespace)
{
struct strbuf buf = STRBUF_INIT;
struct strbuf **components, **c;
if (!raw_namespace || !*raw_namespace)
return xstrdup("");
strbuf_addstr(&buf, raw_namespace);
components = strbuf_split(&buf, '/');
strbuf_reset(&buf);
for (c = components; *c; c++)
if (strcmp((*c)->buf, "/") != 0)
strbuf_addf(&buf, "refs/namespaces/%s", (*c)->buf);
strbuf_list_free(components);
if (check_refname_format(buf.buf, 0))
die("bad git namespace path \"%s\"", raw_namespace);
strbuf_addch(&buf, '/');
return strbuf_detach(&buf, NULL);
}
static void setup_git_env(void)
{
const char *gitfile;
const char *shallow_file;
git_dir = getenv(GIT_DIR_ENVIRONMENT);
if (!git_dir)
git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
gitfile = read_gitfile(git_dir);
git_dir = xstrdup(gitfile ? gitfile : git_dir);
git_object_dir = getenv(DB_ENVIRONMENT);
if (!git_object_dir) {
git_object_dir = xmalloc(strlen(git_dir) + 9);
sprintf(git_object_dir, "%s/objects", git_dir);
}
git_index_file = getenv(INDEX_ENVIRONMENT);
if (!git_index_file) {
git_index_file = xmalloc(strlen(git_dir) + 7);
sprintf(git_index_file, "%s/index", git_dir);
}
git_graft_file = getenv(GRAFT_ENVIRONMENT);
if (!git_graft_file)
git_graft_file = git_pathdup("info/grafts");
if (getenv(NO_REPLACE_OBJECTS_ENVIRONMENT))
check_replace_refs = 0;
namespace = expand_namespace(getenv(GIT_NAMESPACE_ENVIRONMENT));
namespace_len = strlen(namespace);
shallow_file = getenv(GIT_SHALLOW_FILE_ENVIRONMENT);
if (shallow_file)
set_alternate_shallow_file(shallow_file, 0);
}
int is_bare_repository(void)
{
/* if core.bare is not 'false', let's see if there is a work tree */
return is_bare_repository_cfg && !get_git_work_tree();
}
const char *get_git_dir(void)
{
if (!git_dir)
setup_git_env();
return git_dir;
}
const char *get_git_namespace(void)
{
if (!namespace)
setup_git_env();
return namespace;
}
const char *strip_namespace(const char *namespaced_ref)
{
if (!starts_with(namespaced_ref, get_git_namespace()))
return NULL;
return namespaced_ref + namespace_len;
}
static int git_work_tree_initialized;
/*
* Note. This works only before you used a work tree. This was added
* primarily to support git-clone to work in a new repository it just
* created, and is not meant to flip between different work trees.
*/
void set_git_work_tree(const char *new_work_tree)
{
if (git_work_tree_initialized) {
new_work_tree = real_path(new_work_tree);
if (strcmp(new_work_tree, work_tree))
die("internal error: work tree has already been set\n"
"Current worktree: %s\nNew worktree: %s",
work_tree, new_work_tree);
return;
}
git_work_tree_initialized = 1;
work_tree = xstrdup(real_path(new_work_tree));
}
const char *get_git_work_tree(void)
{
return work_tree;
}
char *get_object_directory(void)
{
if (!git_object_dir)
setup_git_env();
return git_object_dir;
}
int odb_mkstemp(char *template, size_t limit, const char *pattern)
{
int fd;
/*
* we let the umask do its job, don't try to be more
* restrictive except to remove write permission.
*/
int mode = 0444;
snprintf(template, limit, "%s/%s",
get_object_directory(), pattern);
fd = git_mkstemp_mode(template, mode);
if (0 <= fd)
return fd;
/* slow path */
/* some mkstemp implementations erase template on failure */
snprintf(template, limit, "%s/%s",
get_object_directory(), pattern);
safe_create_leading_directories(template);
return xmkstemp_mode(template, mode);
}
int odb_pack_keep(char *name, size_t namesz, const unsigned char *sha1)
{
int fd;
snprintf(name, namesz, "%s/pack/pack-%s.keep",
get_object_directory(), sha1_to_hex(sha1));
fd = open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
if (0 <= fd)
return fd;
/* slow path */
safe_create_leading_directories(name);
return open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
}
char *get_index_file(void)
{
if (!git_index_file)
setup_git_env();
return git_index_file;
}
char *get_graft_file(void)
{
if (!git_graft_file)
setup_git_env();
return git_graft_file;
}
int set_git_dir(const char *path)
{
if (setenv(GIT_DIR_ENVIRONMENT, path, 1))
return error("Could not set GIT_DIR to '%s'", path);
setup_git_env();
return 0;
}
const char *get_log_output_encoding(void)
{
return git_log_output_encoding ? git_log_output_encoding
: get_commit_output_encoding();
}
const char *get_commit_output_encoding(void)
{
return git_commit_encoding ? git_commit_encoding : "UTF-8";
}