mirrors/netsurf
1
0
Fork 0
mirror of https://github.com/netsurf-browser/netsurf synced 2024-11-24 15:29:45 +03:00
Code Issues Packages Projects Releases Wiki Activity

allocate small block using block use bitmaps to find free entries.

Browse Source
This commit is contained in:
Vincent Sanders 2015-03-31 00:25:37 +01:00
parent 83fa13b315
commit 9eeae4dd49
1 changed files with 61 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

63
content/fs_backing_store.c
View File

@ -100,7 +100,6 @@
/** length in bytes of a block files use map */
#define BLOCK_USE_MAP_SIZE (1 << (BLOCK_ENTRY_COUNT - 3))
/**
* The type used to store index values refering to store entries. Care
* must be taken with this type as it is used to build address to
@ -204,6 +203,11 @@ struct block_file {
uint8_t use_map[BLOCK_USE_MAP_SIZE];
};
static const unsigned int log2_block_size[] = {
BLOCK_DATA_SIZE,
BLOCK_META_SIZE
};
/**
* Parameters controlling the backing store.
*/
@ -831,6 +835,36 @@ get_store_entry(struct store_state *state, nsurl *url, struct store_entry **bse)
return NSERROR_OK;
}
/**
* Find next available small block.
*/
static block_index_t alloc_block(struct store_state *state, int elem_idx)
{
int bf;
int idx;
int bit;
uint8_t *map;
for (bf = 0; bf < BLOCK_FILE_COUNT; bf++) {
map = &state->blocks[elem_idx][bf].use_map[0];
for (idx = 0; idx < BLOCK_USE_MAP_SIZE; idx++) {
if (*(map + idx) != 0xff) {
/* located an unused block */
for (bit = 0; bit < 8;bit++) {
if (((*(map + idx)) & (1U << bit)) == 0) {
/* mark block as used */
*(map + idx) |= 1U << bit;
state->blocks_dirty = true;
return (((bf * BLOCK_USE_MAP_SIZE) + idx) * 8) + bit;
}
}
}
}
}
return 0;
}
/**
* Set a backing store entry in the entry table from a url.
@ -931,6 +965,12 @@ set_store_entry(struct store_state *state,
elem->size = datalen;
state->total_alloc += elem->size;
/* if the elemnt will fit in a small block attempt to allocate one */
if (elem->size <= (1U << log2_block_size[elem_idx])) {
elem->block = alloc_block(state, elem_idx);
LOG(("Using block %d", elem->block));
}
/* ensure control maintinance scheduled. */
state->entries_dirty = true;
guit->browser->schedule(CONTROL_MAINT_TIME, control_maintinance, state);
@ -1134,6 +1174,8 @@ read_blocks(struct store_state *state)
return ret;
}
LOG(("Initialising block use map from %s", fname));
fd = open(fname, O_RDWR);
free(fname);
if (fd != -1) {
@ -1153,6 +1195,7 @@ read_blocks(struct store_state *state)
close(fd);
} else {
LOG(("Initialising block use map to defaults"));
/* ensure block 0 (invalid sentinal) is skipped */
state->blocks[ENTRY_ELEM_DATA][0].use_map[0] = 1;
state->blocks[ENTRY_ELEM_META][0].use_map[0] = 1;
@ -1458,11 +1501,23 @@ initialise(const struct llcache_store_parameters *parameters)
static nserror
finalise(void)
{
int bf; /* block file index */
if (storestate != NULL) {
guit->browser->schedule(-1, control_maintinance, storestate);
write_entries(storestate);
write_blocks(storestate);
/* ensure all block files are closed */
for (bf = 0; bf < BLOCK_FILE_COUNT; bf++) {
if (storestate->blocks[ENTRY_ELEM_DATA][bf].fd != -1) {
close(storestate->blocks[ENTRY_ELEM_DATA][bf].fd);
}
if (storestate->blocks[ENTRY_ELEM_META][bf].fd != -1) {
close(storestate->blocks[ENTRY_ELEM_META][bf].fd);
}
}
/* avoid division by zero */
if (storestate->miss_count == 0) {
storestate->miss_count = 1;
@ -1494,7 +1549,7 @@ static nserror store_write_block(struct store_state *state,
{
block_index_t bf = (bse->elem[elem_idx].block >> BLOCK_ENTRY_COUNT) &
((1 << BLOCK_FILE_COUNT) - 1); /* block file block resides in */
block_index_t bi = bse->elem[elem_idx].block & ((1 << BLOCK_ENTRY_COUNT) -1); /* block index in file */
block_index_t bi = bse->elem[elem_idx].block & ((1U << BLOCK_ENTRY_COUNT) -1); /* block index in file */
ssize_t wr;
off_t offst;
@ -1518,6 +1573,10 @@ static nserror store_write_block(struct store_state *state,
bse->elem[elem_idx].size,
offst);
LOG(("Wrote %d of %d bytes from %p at %x block %d",
wr, bse->elem[elem_idx].size, bse->elem[elem_idx].data,
offst, bse->elem[elem_idx].block));
if (wr != bse->elem[elem_idx].size) {
return NSERROR_SAVE_FAILED;
}