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Minor clarifications in the code and comments. Integrated atches from Frederic Sureau: 1. copy_buf is now an ordinary char pointer. 2. Read directly from a file that is not modified. This reduces the code size when COFFEE_MICRO_LOGS is set to 0. 3. Update the file end value each time it is changed in case a log merge operation occurs later. 4. Avoid possible alignment problem in reading from the dummy_space area when calling cfs_readdir.

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This commit is contained in:
nvt-se 2010-11-11 13:08:23 +00:00
parent 24614875ef
commit 1168703506
1 changed files with 43 additions and 24 deletions
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67
core/cfs/cfs-coffee.c
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@ -937,7 +937,7 @@ write_log_page(struct file *file, struct log_param *lp)
}
{
unsigned char copy_buf[log_record_size];
char copy_buf[log_record_size];
lp_out.offset = offset = region * log_record_size;
lp_out.buf = copy_buf;
@ -949,8 +949,12 @@ write_log_page(struct file *file, struct log_param *lp)
absolute_offset(file->page, offset));
}
memcpy((char *)&copy_buf + lp->offset, lp->buf, lp->size);
memcpy(&copy_buf[lp->offset], lp->buf, lp->size);
/*
* Write the region number in the region index table.
* The region number is incremented to avoid values of zero.
*/
offset = absolute_offset(log_page, 0);
++region;
COFFEE_WRITE(&region, sizeof(region),
@ -1098,35 +1102,39 @@ cfs_read(int fd, void *buf, unsigned size)
size = file->end - fdp->offset;
}
bytes_left = size;
if(FILE_MODIFIED(file)) {
read_header(&hdr, file->page);
/* If the file is allocated, read directly in the file. */
if(!FILE_MODIFIED(file)) {
COFFEE_READ(buf, size, absolute_offset(file->page, fdp->offset));
fdp->offset += size;
return size;
}
#if COFFEE_MICRO_LOGS
read_header(&hdr, file->page);
/*
* Fill the buffer by copying from the log in first hand, or the
* ordinary file if the page has no log record.
*/
while(bytes_left) {
for(bytes_left = size; bytes_left > 0; bytes_left -= r) {
watchdog_periodic();
r = -1;
#if COFFEE_MICRO_LOGS
if(FILE_MODIFIED(file)) {
lp.offset = fdp->offset;
lp.buf = buf;
lp.size = bytes_left;
r = read_log_page(&hdr, file->record_count, &lp);
}
#endif /* COFFEE_MICRO_LOGS */
lp.offset = fdp->offset;
lp.buf = buf;
lp.size = bytes_left;
r = read_log_page(&hdr, file->record_count, &lp);
/* Read from the original file if we cannot find the data in the log. */
if(r < 0) {
COFFEE_READ(buf, bytes_left, absolute_offset(file->page, fdp->offset));
r = bytes_left;
COFFEE_READ(buf, r, absolute_offset(file->page, fdp->offset));
}
bytes_left -= r;
fdp->offset += r;
buf += r;
}
#endif /* COFFEE_MICRO_LOGS */
return size;
}
/*---------------------------------------------------------------------------*/
@ -1160,8 +1168,7 @@ cfs_write(int fd, const void *buf, unsigned size)
#if COFFEE_MICRO_LOGS
if(FILE_MODIFIED(file) || fdp->offset < file->end) {
bytes_left = size;
while(bytes_left) {
for(bytes_left = size; bytes_left > 0;) {
lp.offset = fdp->offset;
lp.buf = buf;
lp.size = bytes_left;
@ -1180,6 +1187,12 @@ cfs_write(int fd, const void *buf, unsigned size)
bytes_left -= i;
fdp->offset += i;
buf += i;
/* Update the file end for a potential log merge that might
occur while writing log records. */
if(fdp->offset > file->end) {
file->end = fdp->offset;
}
}
}
@ -1190,10 +1203,11 @@ cfs_write(int fd, const void *buf, unsigned size)
} else {
#endif /* COFFEE_MICRO_LOGS */
#if COFFEE_APPEND_ONLY
if(fdp->offset < file->end) {
return -1;
}
if(fdp->offset < file->end) {
return -1;
}
#endif /* COFFEE_APPEND_ONLY */
COFFEE_WRITE(buf, size, absolute_offset(file->page, fdp->offset));
fdp->offset += size;
#if COFFEE_MICRO_LOGS
@ -1214,7 +1228,7 @@ cfs_opendir(struct cfs_dir *dir, const char *name)
* Coffee is only guaranteed to support "/" and ".", but it does not
* currently enforce this.
*/
*(coffee_page_t *)dir->dummy_space = 0;
memset(dir->dummy_space, 0, sizeof(coffee_page_t));
return 0;
}
/*---------------------------------------------------------------------------*/
@ -1224,14 +1238,19 @@ cfs_readdir(struct cfs_dir *dir, struct cfs_dirent *record)
struct file_header hdr;
coffee_page_t page;
for(page = *(coffee_page_t *)dir->dummy_space; page < COFFEE_PAGE_COUNT;) {
memcpy(&page, dir->dummy_space, sizeof(coffee_page_t));
while(page < COFFEE_PAGE_COUNT) {
watchdog_periodic();
read_header(&hdr, page);
if(HDR_ACTIVE(hdr) && !HDR_LOG(hdr)) {
coffee_page_t next_page;
memcpy(record->name, hdr.name, sizeof(record->name));
record->name[sizeof(record->name) - 1] = '\0';
record->size = file_end(page);
*(coffee_page_t *)dir->dummy_space = next_file(page, &hdr);
next_page = next_file(page, &hdr);
memcpy(dir->dummy_space, &next_page, sizeof(coffee_page_t));
return 0;
}
page = next_file(page, &hdr);