/*---------------------------------------------------------------------------*/
int
cfs_read(int fd, void *buf, unsigned size)
{
struct file_header hdr;
struct file_desc *fdp;
struct file *file;
unsigned bytes_left;
int r;
#if COFFEE_MICRO_LOGS
struct log_param lp;
#endif
if(!(FD_VALID(fd) && FD_READABLE(fd))) {
return -1;
}
fdp = &coffee_fd_set[fd];
file = fdp->file;
if(fdp->offset + size > file->end) {
size = file->end - fdp->offset;
}
bytes_left = size;
if(FILE_MODIFIED(file)) {
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) {
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 */
/* Read from the original file if we cannot find the data in the log. */
if(r < 0) {
r = bytes_left;
COFFEE_READ(buf, r, absolute_offset(file->page, fdp->offset));
}
bytes_left -= r;
fdp->offset += r;
buf += r;
}
return size;
}
/*---------------------------------------------------------------------------*/
int
cfs_read(int fd, void *buf, unsigned size)
{
struct file_desc *fdp;
struct file *file;
#if COFFEE_MICRO_LOGS
struct file_header hdr;
struct log_param lp;
unsigned bytes_left;
int r;
#endif
if(!(FD_VALID(fd) && FD_READABLE(fd))) {
return -1;
}
fdp = &coffee_fd_set[fd];
file = fdp->file;
if(fdp->offset + size > file->end) {
size = file->end - fdp->offset;
}
/* 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.
*/
for(bytes_left = size; bytes_left > 0; bytes_left -= r) {
r = -1;
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, lp.size, absolute_offset(file->page, fdp->offset));
r = lp.size;
}
fdp->offset += r;
buf = (char *)buf + r;
}
#endif /* COFFEE_MICRO_LOGS */
return size;
}
/*---------------------------------------------------------------------------*/
int
cfs_read(int fd, void *buf, unsigned size)
{
struct file_desc *fdp;
struct file *file;
#if COFFEE_MICRO_LOGS
struct file_header hdr;
struct log_param lp;
unsigned bytes_left;
int r;
#endif
if(!(FD_VALID(fd) && FD_READABLE(fd))) {
return -1;
}
fdp = &coffee_fd_set[fd];
file = fdp->file;
if(fdp->offset + size > file->end) {
size = file->end - fdp->offset;
}
/* If the file is not modified, read directly from the file extent. */
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);
/*
* Copy the contents of the most recent log record. If there is
* no log record for the file area to read from, we simply read
* from the original file extent.
*/
for(bytes_left = size; bytes_left > 0; bytes_left -= r) {
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, lp.size, absolute_offset(file->page, fdp->offset));
r = lp.size;
}
fdp->offset += r;
buf = (char *)buf + r;
}
#endif /* COFFEE_MICRO_LOGS */
return size;
}
/*---------------------------------------------------------------------------*/
int
cfs_write(int fd, const void *buf, unsigned size)
{
struct file_desc *fdp;
struct file *file;
#if COFFEE_MICRO_LOGS
int i;
struct log_param lp;
cfs_offset_t bytes_left;
const char dummy[1] = { 0xff };
#endif
if(!(FD_VALID(fd) && FD_WRITABLE(fd))) {
return -1;
}
fdp = &coffee_fd_set[fd];
file = fdp->file;
/* Attempt to extend the file if we try to write past the end. */
#if COFFEE_IO_SEMANTICS
if(!(fdp->io_flags & CFS_COFFEE_IO_FIRM_SIZE)) {
#endif
while(size + fdp->offset + sizeof(struct file_header) >
(file->max_pages * COFFEE_PAGE_SIZE)) {
if(merge_log(file->page, 1) < 0) {
return -1;
}
file = fdp->file;
PRINTF(("Extended the file at page %u\n", (unsigned)file->page));
}
#if COFFEE_IO_SEMANTICS
}
#endif
#if COFFEE_MICRO_LOGS
#if COFFEE_IO_SEMANTICS
if(!(fdp->io_flags & CFS_COFFEE_IO_FLASH_AWARE) &&
(FILE_MODIFIED(file) || fdp->offset < file->end)) {
#else
if(FILE_MODIFIED(file) || fdp->offset < file->end) {
#endif
for(bytes_left = size; bytes_left > 0;) {
lp.offset = fdp->offset;
lp.buf = buf;
lp.size = bytes_left;
i = write_log_page(file, &lp);
if(i < 0) {
/* Return -1 if we wrote nothing because the log write failed. */
if(size == bytes_left) {
return -1;
}
break;
} else if(i == 0) {
/* The file was merged with the log. */
file = fdp->file;
} else {
/* A log record was written. */
bytes_left -= i;
fdp->offset += i;
buf = (char *)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;
}
}
}
if(fdp->offset > file->end) {
/* Update the original file's end with a dummy write. */
COFFEE_WRITE(dummy, 1, absolute_offset(file->page, fdp->offset));
}
} else {
#endif /* COFFEE_MICRO_LOGS */
#if COFFEE_APPEND_ONLY
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
}
#endif /* COFFEE_MICRO_LOGS */
if(fdp->offset > file->end) {
file->end = fdp->offset;
}
return size;
}
/*---------------------------------------------------------------------------*/
int
cfs_opendir(struct cfs_dir *dir, const char *name)
{
/*
* Coffee is only guaranteed to support "/" and ".", but it does not
* currently enforce this.
*/
memset(dir->dummy_space, 0, sizeof(coffee_page_t));
return 0;
}
/*---------------------------------------------------------------------------*/
int
cfs_write(int fd, const void *buf, unsigned size)
{
struct file_desc *fdp;
struct file *file;
#if COFFEE_MICRO_LOGS
int i;
struct log_param lp;
cfs_offset_t bytes_left;
const char dummy[1] = { 0xff };
#endif
if(!(FD_VALID(fd) && FD_WRITABLE(fd))) {
return -1;
}
fdp = &coffee_fd_set[fd];
file = fdp->file;
/* Attempt to extend the file if we try to write past the end. */
while(size + fdp->offset + sizeof(struct file_header) >
(file->max_pages * COFFEE_PAGE_SIZE)) {
if(merge_log(file->page, 1) < 0) {
return -1;
}
file = fdp->file;
PRINTF("Extended the file at page %u\n", (unsigned)file->page);
}
#if COFFEE_MICRO_LOGS
if(FILE_MODIFIED(file) || fdp->offset < file->end) {
bytes_left = size;
while(bytes_left) {
lp.offset = fdp->offset;
lp.buf = buf;
lp.size = bytes_left;
i = write_log_page(file, &lp);
if(i < 0) {
/* Return -1 if we wrote nothing because the log write failed. */
if(size == bytes_left) {
return -1;
}
break;
} else if(i == 0) {
/* The file was merged with the log. */
file = fdp->file;
} else {
/* A log record was written. */
bytes_left -= i;
fdp->offset += i;
buf += i;
}
}
if(fdp->offset > file->end) {
/* Update the original file's end with a dummy write. */
COFFEE_WRITE(dummy, 1, absolute_offset(file->page, fdp->offset));
}
} else {
#endif /* COFFEE_MICRO_LOGS */
#if COFFEE_APPEND_ONLY
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
}
#endif /* COFFEE_MICRO_LOGS */
if(fdp->offset > file->end) {
file->end = fdp->offset;
}
return size;
}