@@ -3,14 +3,16 @@ index.recordEndOfIndexEntries::
Entry" section. This reduces index load time on multiprocessor
machines but produces a message "ignoring EOIE extension" when
reading the index using Git versions before 2.20. Defaults to
- 'false'.
+ 'true' if index.threads has been explicitly enabled, 'false'
+ otherwise.
index.recordOffsetTable::
Specifies whether the index file should include an "Index Entry
Offset Table" section. This reduces index load time on
multiprocessor machines but produces a message "ignoring IEOT
extension" when reading the index using Git versions before 2.20.
- Defaults to 'false'.
+ Defaults to 'true' if index.threads has been explicitly enabled,
+ 'false' otherwise.
index.threads::
Specifies the number of threads to spawn when loading the index.
@@ -2294,22 +2294,25 @@ int git_config_get_fsmonitor(void)
return 0;
}
-int git_config_get_index_threads(void)
+int git_config_get_index_threads(int *dest)
{
- int is_bool, val = 0;
+ int is_bool, val;
val = git_env_ulong("GIT_TEST_INDEX_THREADS", 0);
- if (val)
- return val;
+ if (val) {
+ *dest = val;
+ return 0;
+ }
if (!git_config_get_bool_or_int("index.threads", &is_bool, &val)) {
if (is_bool)
- return val ? 0 : 1;
+ *dest = val ? 0 : 1;
else
- return val;
+ *dest = val;
+ return 0;
}
- return 0; /* auto */
+ return 1;
}
NORETURN
@@ -246,11 +246,11 @@ extern int git_config_get_bool(const char *key, int *dest);
extern int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest);
extern int git_config_get_maybe_bool(const char *key, int *dest);
extern int git_config_get_pathname(const char *key, const char **dest);
+extern int git_config_get_index_threads(int *dest);
extern int git_config_get_untracked_cache(void);
extern int git_config_get_split_index(void);
extern int git_config_get_max_percent_split_change(void);
extern int git_config_get_fsmonitor(void);
-extern int git_config_get_index_threads(void);
/* This dies if the configured or default date is in the future */
extern int git_config_get_expiry(const char *key, const char **output);
@@ -2176,7 +2176,8 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
src_offset = sizeof(*hdr);
- nr_threads = git_config_get_index_threads();
+ if (git_config_get_index_threads(&nr_threads))
+ nr_threads = 1;
/* TODO: does creating more threads than cores help? */
if (!nr_threads) {
@@ -2695,7 +2696,13 @@ static int record_eoie(void)
if (!git_config_get_bool("index.recordendofindexentries", &val))
return val;
- return 0;
+
+ /*
+ * As a convenience, the end of index entries extension
+ * used for threading is written by default if the user
+ * explicitly requested threaded index reads.
+ */
+ return !git_config_get_index_threads(&val) && val != 1;
}
static int record_ieot(void)
@@ -2704,7 +2711,13 @@ static int record_ieot(void)
if (!git_config_get_bool("index.recordoffsettable", &val))
return val;
- return 0;
+
+ /*
+ * As a convenience, the offset table used for threading is
+ * written by default if the user explicitly requested
+ * threaded index reads.
+ */
+ return !git_config_get_index_threads(&val) && val != 1;
}
/*
@@ -2765,9 +2778,7 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
return -1;
- if (HAVE_THREADS)
- nr_threads = git_config_get_index_threads();
- else
+ if (!HAVE_THREADS || git_config_get_index_threads(&nr_threads))
nr_threads = 1;
if (nr_threads != 1 && record_ieot()) {
If a user explicitly sets [index] threads = true to read the index using multiple threads, ensure that index writes include the offset table by default to make that possible. This ensures that the user's intent of turning on threading is respected. In other words, permit the following configurations: - index.threads and index.recordOffsetTable unspecified: do not write the offset table yet (to avoid alarming the user with "ignoring IEOT extension" messages when an older version of Git accesses the repository) but do make use of multiple threads to read the index if the supporting offset table is present. This can also be requested explicitly by setting index.threads=true, 0, or >1 and index.recordOffsetTable=false. - index.threads=false or 1: do not write the offset table, and do not make use of the offset table. One can set index.recordOffsetTable=false as well, to be more explicit. - index.threads=true, 0, or >1 and index.recordOffsetTable unspecified: write the offset table and make use of threads at read time. This can also be requested by setting index.threads=true, 0, >1, or unspecified and index.recordOffsetTable=true. Fortunately the complication is temporary: once most Git installations have upgraded to a version with support for the IEOT and EOIE extensions, we can flip the defaults for index.recordEndOfIndexEntries and index.recordOffsetTable to true and eliminate the settings. Helped-by: Ben Peart <benpeart@microsoft.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> --- New, based on Ben Peart's feedback. Turned out simpler than I feared --- thanks, Ben, for pushing for this. Documentation/config/index.txt | 6 ++++-- config.c | 17 ++++++++++------- config.h | 2 +- read-cache.c | 23 +++++++++++++++++------ 4 files changed, 32 insertions(+), 16 deletions(-)