deac/osd-contiki
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

Clarified and cleaned up Coffee's documentation and the debug statements. Formatted some source code for easier reading.

Browse source
This commit is contained in:
Nicolas Tsiftes 2016-04-20 14:30:20 +02:00
parent 7586195b79
commit 86733e8702
2 changed files with 56 additions and 62 deletions
Download patch file Download diff file Expand all files Collapse all files

77
core/cfs/cfs-coffee.c
View file

@ -114,41 +114,41 @@
#define GC_RELUCTANT 1
/* File descriptor macros. */
#define FD_VALID(fd) \
((fd) >= 0 && (fd) < COFFEE_FD_SET_SIZE && \
coffee_fd_set[(fd)].flags != COFFEE_FD_FREE)
#define FD_VALID(fd) ((fd) >= 0 && (fd) < COFFEE_FD_SET_SIZE && \
coffee_fd_set[(fd)].flags != COFFEE_FD_FREE)
#define FD_READABLE(fd) (coffee_fd_set[(fd)].flags & CFS_READ)
#define FD_WRITABLE(fd) (coffee_fd_set[(fd)].flags & CFS_WRITE)
#define FD_APPENDABLE(fd) (coffee_fd_set[(fd)].flags & CFS_APPEND)
/* File object macros. */
#define FILE_MODIFIED(file) ((file)->flags & COFFEE_FILE_MODIFIED)
#define FILE_FREE(file) ((file)->max_pages == 0)
#define FILE_MODIFIED(file) ((file)->flags & COFFEE_FILE_MODIFIED)
#define FILE_FREE(file) ((file)->max_pages == 0)
#define FILE_UNREFERENCED(file) ((file)->references == 0)
/* File header flags. */
#define HDR_FLAG_VALID 0x1 /* Completely written header. */
#define HDR_FLAG_ALLOCATED 0x2 /* Allocated file. */
#define HDR_FLAG_OBSOLETE 0x4 /* File marked for GC. */
#define HDR_FLAG_MODIFIED 0x8 /* Modified file, log exists. */
#define HDR_FLAG_LOG 0x10 /* Log file. */
#define HDR_FLAG_ISOLATED 0x20 /* Isolated page. */
#define HDR_FLAG_VALID 0x01 /* Completely written header. */
#define HDR_FLAG_ALLOCATED 0x02 /* Allocated file. */
#define HDR_FLAG_OBSOLETE 0x04 /* File marked for GC. */
#define HDR_FLAG_MODIFIED 0x08 /* Modified file, log exists. */
#define HDR_FLAG_LOG 0x10 /* Log file. */
#define HDR_FLAG_ISOLATED 0x20 /* Isolated page. */
/* File header macros. */
#define CHECK_FLAG(hdr, flag) ((hdr).flags & (flag))
#define HDR_VALID(hdr) CHECK_FLAG(hdr, HDR_FLAG_VALID)
#define HDR_ALLOCATED(hdr) CHECK_FLAG(hdr, HDR_FLAG_ALLOCATED)
#define HDR_FREE(hdr) !HDR_ALLOCATED(hdr)
#define HDR_LOG(hdr) CHECK_FLAG(hdr, HDR_FLAG_LOG)
#define HDR_MODIFIED(hdr) CHECK_FLAG(hdr, HDR_FLAG_MODIFIED)
#define HDR_ISOLATED(hdr) CHECK_FLAG(hdr, HDR_FLAG_ISOLATED)
#define HDR_OBSOLETE(hdr) CHECK_FLAG(hdr, HDR_FLAG_OBSOLETE)
#define HDR_ACTIVE(hdr) (HDR_ALLOCATED(hdr) && \
!HDR_OBSOLETE(hdr) && \
!HDR_ISOLATED(hdr))
#define HDR_VALID(hdr) CHECK_FLAG(hdr, HDR_FLAG_VALID)
#define HDR_ALLOCATED(hdr) CHECK_FLAG(hdr, HDR_FLAG_ALLOCATED)
#define HDR_FREE(hdr) !HDR_ALLOCATED(hdr)
#define HDR_LOG(hdr) CHECK_FLAG(hdr, HDR_FLAG_LOG)
#define HDR_MODIFIED(hdr) CHECK_FLAG(hdr, HDR_FLAG_MODIFIED)
#define HDR_ISOLATED(hdr) CHECK_FLAG(hdr, HDR_FLAG_ISOLATED)
#define HDR_OBSOLETE(hdr) CHECK_FLAG(hdr, HDR_FLAG_OBSOLETE)
#define HDR_ACTIVE(hdr) (HDR_ALLOCATED(hdr) && \
!HDR_OBSOLETE(hdr) && \
!HDR_ISOLATED(hdr))
/* Shortcuts derived from the hardware-dependent configuration of Coffee. */
#define COFFEE_SECTOR_COUNT (unsigned)(COFFEE_SIZE / COFFEE_SECTOR_SIZE)
#define COFFEE_SECTOR_COUNT \
(coffee_page_t)(COFFEE_SIZE / COFFEE_SECTOR_SIZE)
#define COFFEE_PAGE_COUNT \
((coffee_page_t)(COFFEE_SIZE / COFFEE_PAGE_SIZE))
#define COFFEE_PAGES_PER_SECTOR \
@ -235,7 +235,7 @@ absolute_offset(coffee_page_t page, cfs_offset_t offset)
}
/*---------------------------------------------------------------------------*/
static coffee_page_t
get_sector_status(uint16_t sector, struct sector_status *stats)
get_sector_status(coffee_page_t sector, struct sector_status *stats)
{
static coffee_page_t skip_pages;
static char last_pages_are_active;
@ -305,7 +305,7 @@ get_sector_status(uint16_t sector, struct sector_status *stats)
/*
* Determine the amount of pages in the following sectors that
* should be remembered for the next iteration. This is necessary
* because no page except the first of a file contains information
* because no file page except the first contains information
* about what type of page it is. A side effect of remembering this
* amount is that there is no need to read in the headers of each
* of these pages from the storage.
@ -356,11 +356,11 @@ isolate_pages(coffee_page_t start, coffee_page_t skip_pages)
static void
collect_garbage(int mode)
{
uint16_t sector;
coffee_page_t sector;
struct sector_status stats;
coffee_page_t first_page, isolation_count;
PRINTF("Coffee: Running the file system garbage collector in %s mode\n",
PRINTF("Coffee: Running the garbage collector in %s mode\n",
mode == GC_RELUCTANT ? "reluctant" : "greedy");
/*
* The garbage collector erases as many sectors as possible. A sector is
@ -369,7 +369,7 @@ collect_garbage(int mode)
for(sector = 0; sector < COFFEE_SECTOR_COUNT; sector++) {
isolation_count = get_sector_status(sector, &stats);
PRINTF("Coffee: Sector %u has %u active, %u obsolete, and %u free pages.\n",
sector, (unsigned)stats.active,
(unsigned)sector, (unsigned)stats.active,
(unsigned)stats.obsolete, (unsigned)stats.free);
if(stats.active > 0) {
@ -402,7 +402,7 @@ next_file(coffee_page_t page, struct file_header *hdr)
{
/*
* The quick-skip algorithm for finding file extents is the most
* essential part of Coffee. The file allocation rules enables this
* essential part of Coffee. The file allocation rules enable this
* algorithm to quickly jump over free areas and allocated extents
* after reading single headers and determining their status.
*
@ -648,7 +648,7 @@ reserve(const char *name, coffee_page_t pages,
write_header(&hdr, page);
PRINTF("Coffee: Reserved %u pages starting from %u for file %s\n",
pages, page, name);
(unsigned)pages, (unsigned)page, name);
file = load_file(page, &hdr);
if(file != NULL) {
@ -843,7 +843,7 @@ merge_log(coffee_page_t file_page, int extend)
return -1;
}
/* Copy the log configuration and the EOF hint. */
/* Copy the log configuration. */
read_header(&hdr2, new_file->page);
hdr2.log_record_size = hdr.log_record_size;
hdr2.log_records = hdr.log_records;
@ -1102,7 +1102,7 @@ cfs_read(int fd, void *buf, unsigned size)
size = file->end - fdp->offset;
}
/* If the file is allocated, read directly in the file. */
/* 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;
@ -1113,8 +1113,9 @@ cfs_read(int fd, void *buf, unsigned size)
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.
* 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;
@ -1242,8 +1243,8 @@ int
cfs_opendir(struct cfs_dir *dir, const char *name)
{
/*
* Coffee is only guaranteed to support "/" and ".", but it does not
* currently enforce this.
* Coffee is only guaranteed to support the directory names "/" and ".",
* but it does not enforce this currently.
*/
memset(dir->dummy_space, 0, sizeof(coffee_page_t));
return 0;
@ -1254,13 +1255,13 @@ cfs_readdir(struct cfs_dir *dir, struct cfs_dirent *record)
{
struct file_header hdr;
coffee_page_t page;
coffee_page_t next_page;
memcpy(&page, dir->dummy_space, sizeof(coffee_page_t));
while(page < COFFEE_PAGE_COUNT) {
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);
@ -1334,9 +1335,9 @@ cfs_coffee_set_io_semantics(int fd, unsigned flags)
int
cfs_coffee_format(void)
{
unsigned i;
coffee_page_t i;
PRINTF("Coffee: Formatting %u sectors", COFFEE_SECTOR_COUNT);
PRINTF("Coffee: Formatting %u sectors", (unsigned)COFFEE_SECTOR_COUNT);
for(i = 0; i < COFFEE_SECTOR_COUNT; i++) {
COFFEE_ERASE(i);