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authorJunio C Hamano <junkio@cox.net>2005-10-08 22:54:36 (GMT)
committerJunio C Hamano <junkio@cox.net>2005-10-08 22:54:36 (GMT)
commitf48000fcbe1009c18f1cc46e56cde2cb632071fa (patch)
tree1f0fe466ecfb4a026a5fdf1790576171b118fbf2 /compat/mmap.c
parent730d48a2ef88a7fb7aa4409d40b1e6964a93267f (diff)
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Yank writing-back support from gitfakemmap.
We do not write through our use of mmap(), so make sure callers pass MAP_PRIVATE and remove support for writing changes back. Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'compat/mmap.c')
-rw-r--r--compat/mmap.c75
1 files changed, 6 insertions, 69 deletions
diff --git a/compat/mmap.c b/compat/mmap.c
index fca6321..a051c47 100644
--- a/compat/mmap.c
+++ b/compat/mmap.c
@@ -4,43 +4,33 @@
#include <errno.h>
#include "../cache.h"
-typedef struct fakemmapwritable {
- void *start;
- size_t length;
- int fd;
- off_t offset;
- struct fakemmapwritable *next;
-} fakemmapwritable;
-
-static fakemmapwritable *writablelist = NULL;
-
void *gitfakemmap(void *start, size_t length, int prot , int flags, int fd, off_t offset)
{
int n = 0;
- if(start != NULL)
+ if (start != NULL || !(flags & MAP_PRIVATE))
die("Invalid usage of gitfakemmap.");
- if(lseek(fd, offset, SEEK_SET)<0) {
+ if (lseek(fd, offset, SEEK_SET) < 0) {
errno = EINVAL;
return MAP_FAILED;
}
start = xmalloc(length);
- if(start == NULL) {
+ if (start == NULL) {
errno = ENOMEM;
return MAP_FAILED;
}
- while(n < length) {
+ while (n < length) {
int count = read(fd, start+n, length-n);
- if(count == 0) {
+ if (count == 0) {
memset(start+n, 0, length-n);
break;
}
- if(count < 0) {
+ if (count < 0) {
free(start);
errno = EACCES;
return MAP_FAILED;
@@ -49,65 +39,12 @@ void *gitfakemmap(void *start, size_t length, int prot , int flags, int fd, off_
n += count;
}
- if(prot & PROT_WRITE) {
- fakemmapwritable *next = xmalloc(sizeof(fakemmapwritable));
- next->start = start;
- next->length = length;
- next->fd = dup(fd);
- next->offset = offset;
- next->next = writablelist;
- writablelist = next;
- }
-
return start;
}
int gitfakemunmap(void *start, size_t length)
{
- fakemmapwritable *writable = writablelist, *before = NULL;
-
- while(writable && (writable->start > start + length
- || writable->start + writable->length < start)) {
- before = writable;
- writable = writable->next;
- }
-
- if(writable) {
- /* need to write back the contents */
- int n = 0;
-
- if(writable->start != start || writable->length != length)
- die("fakemmap does not support partial write back.");
-
- if(lseek(writable->fd, writable->offset, SEEK_SET) < 0) {
- free(start);
- errno = EBADF;
- return -1;
- }
-
- while(n < length) {
- int count = write(writable->fd, start + n, length - n);
-
- if(count < 0) {
- errno = EINVAL;
- return -1;
- }
-
- n += count;
- }
-
- close(writable->fd);
-
- if(before)
- before->next = writable->next;
- else
- writablelist = writable->next;
-
- free(writable);
- }
-
free(start);
-
return 0;
}