From: Marius Storm-Olsen <marius@xxxxxxxxxxxxx>
The original readdir implementation was fast, but didn't
support the d_type. This means that git would do additional
lstats for each entry, to figure out if the entry was a
directory or not. This unneedingly slowed down many
operations, since Windows API provides this information
directly when walking the directories.
By running this implementation on Moe's repo structure:
mkdir bummer && cd bummer; for ((i=0;i<100;i++)); do
mkdir $i && pushd $i;
for ((j=0;j<1000;j++)); do echo "$j" >$j; done;
popd;
done
We see the following speedups:
git add .
-------------------
old: 00:00:23(.087)
new: 00:00:21(.512) 1.07x
git status
-------------------
old: 00:00:03(.306)
new: 00:00:01(.684) 1.96x
git clean -dxf
-------------------
old: 00:00:01(.918)
new: 00:00:00(.295) 6.50x
Signed-off-by: Marius Storm-Olsen <marius@xxxxxxxxxxxxx>
Signed-off-by: Steffen Prohaska <prohaska@xxxxxx>
---
compat/mingw.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
compat/mingw.h | 29 +++++++++++++++++++++++++++
2 files changed, 88 insertions(+), 0 deletions(-)
diff --git a/compat/mingw.c b/compat/mingw.c
index e190fdd..d85d680 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -1171,3 +1171,62 @@ char *getpass(const char *prompt)
fputs("\n", stderr);
return strbuf_detach(&buf, NULL);
}
+
+#ifndef NO_MINGW_REPLACE_READDIR
+/* MinGW readdir implementation to avoid extra lstats for Git */
+struct mingw_DIR
+{
+ struct _finddata_t dd_dta; /* disk transfer area for this dir */
+ struct mingw_dirent dd_dir; /* Our own implementation, including d_type */
+ long dd_handle; /* _findnext handle */
+ int dd_stat; /* 0 = next entry to read is first entry, -1 = off the end, positive = 0 based index of next entry */
+ char dd_name[1]; /* given path for dir with search pattern (struct is extended) */
+};
+
+struct dirent *mingw_readdir(DIR *dir)
+{
+ WIN32_FIND_DATAA buf;
+ HANDLE handle;
+ struct mingw_DIR *mdir = (struct mingw_DIR*)dir;
+
+ if (!dir->dd_handle) {
+ errno = EBADF; /* No set_errno for mingw */
+ return NULL;
+ }
+
+ if (dir->dd_handle == (long)INVALID_HANDLE_VALUE && dir->dd_stat == 0)
+ {
+ handle = FindFirstFileA(dir->dd_name, &buf);
+ DWORD lasterr = GetLastError();
+ dir->dd_handle = (long)handle;
+ if (handle == INVALID_HANDLE_VALUE && (lasterr != ERROR_NO_MORE_FILES)) {
+ errno = err_win_to_posix(lasterr);
+ return NULL;
+ }
+ } else if (dir->dd_handle == (long)INVALID_HANDLE_VALUE) {
+ return NULL;
+ } else if (!FindNextFileA((HANDLE)dir->dd_handle, &buf)) {
+ DWORD lasterr = GetLastError();
+ FindClose((HANDLE)dir->dd_handle);
+ dir->dd_handle = (long)INVALID_HANDLE_VALUE;
+ /* POSIX says you shouldn't set errno when readdir can't
+ find any more files; so, if another error we leave it set. */
+ if (lasterr != ERROR_NO_MORE_FILES)
+ errno = err_win_to_posix(lasterr);
+ return NULL;
+ }
+
+ /* We get here if `buf' contains valid data. */
+ strcpy(dir->dd_dir.d_name, buf.cFileName);
+ ++dir->dd_stat;
+
+ /* Set file type, based on WIN32_FIND_DATA */
+ mdir->dd_dir.d_type = 0;
+ if (buf.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
+ mdir->dd_dir.d_type |= DT_DIR;
+ else
+ mdir->dd_dir.d_type |= DT_REG;
+
+ return (struct dirent*)&dir->dd_dir;
+}
+#endif // !NO_MINGW_REPLACE_READDIR
diff --git a/compat/mingw.h b/compat/mingw.h
index 4c50f5b..4f7ba4c 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -235,3 +235,32 @@ int main(int argc, const char **argv) \
return mingw_main(argc, argv); \
} \
static int mingw_main(c,v)
+
+#ifndef NO_MINGW_REPLACE_READDIR
+/*
+ * A replacement of readdir, to ensure that it reads the file type at
+ * the same time. This avoid extra unneeded lstats in git on MinGW
+ */
+#undef DT_UNKNOWN
+#undef DT_DIR
+#undef DT_REG
+#undef DT_LNK
+#define DT_UNKNOWN 0
+#define DT_DIR 1
+#define DT_REG 2
+#define DT_LNK 3
+
+struct mingw_dirent
+{
+ long d_ino; /* Always zero. */
+ union {
+ unsigned short d_reclen; /* Always zero. */
+ unsigned char d_type; /* Reimplementation adds this */
+ };
+ unsigned short d_namlen; /* Length of name in d_name. */
+ char d_name[FILENAME_MAX]; /* File name. */
+};
+#define dirent mingw_dirent
+#define readdir(x) mingw_readdir(x)
+struct dirent *mingw_readdir(DIR *dir);
+#endif // !NO_MINGW_REPLACE_READDIR
--
1.6.3.1.54.g99dd
--
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