diff options
Diffstat (limited to 'strcache.c')
| -rw-r--r-- | strcache.c | 72 |
1 files changed, 48 insertions, 24 deletions
@@ -20,8 +20,9 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "hash.h" -/* The size (in bytes) of each cache buffer. */ -#define CACHE_BUFFER_SIZE (4096) +/* The size (in bytes) of each cache buffer. + Try to pick something that will map well into the heap. */ +#define CACHE_BUFFER_SIZE (8192 - 16) /* A string cached here will never be freed, so we don't need to worry about @@ -39,6 +40,11 @@ struct strcache { static int bufsize = CACHE_BUFFER_SIZE; static struct strcache *strcache = NULL; +/* Add a new buffer to the cache. Add it at the front to reduce search time. + This can also increase the overhead, since it's less likely that older + buffers will be filled in. However, GNU make has so many smaller strings + that this doesn't seem to be much of an issue in practice. + */ static struct strcache * new_cache() { @@ -61,9 +67,9 @@ add_string(const char *str, int len) struct strcache *sp; const char *res; - /* If the string we want is too large to fit into a single buffer, then we're - screwed; nothing will ever fit! Change the maximum size of the cache to - be big enough. */ + /* If the string we want is too large to fit into a single buffer, then + we're screwed; nothing will ever fit! Change the maximum size of the + cache to be big enough. */ if (len > bufsize) bufsize = len * 2; @@ -113,6 +119,7 @@ str_hash_cmp (const void *x, const void *y) } static struct hash_table strings; +static unsigned long total_adds = 0; static const char * add_hash (const char *str, int len) @@ -121,6 +128,9 @@ add_hash (const char *str, int len) char *const *slot = (char *const *) hash_find_slot (&strings, str); const char *key = *slot; + /* Count the total number of adds we performed. */ + ++total_adds; + if (!HASH_VACANT (key)) return key; @@ -179,7 +189,7 @@ strcache_setbufsize(int size) void strcache_init (void) { - hash_init (&strings, 1000, str_hash_1, str_hash_2, str_hash_cmp); + hash_init (&strings, 8000, str_hash_1, str_hash_2, str_hash_cmp); } @@ -191,32 +201,46 @@ strcache_print_stats (const char *prefix) int numbuffs = 0, numstrs = 0; int totsize = 0, avgsize, maxsize = 0, minsize = bufsize; int totfree = 0, avgfree, maxfree = 0, minfree = bufsize; - const struct strcache *sp; + int lastused = 0, lastfree = 0; - for (sp = strcache; sp != NULL; sp = sp->next) + if (strcache) { - int bf = sp->bytesfree; - int sz = (sp->end - sp->buffer) + bf; + const struct strcache *sp; + + /* Count the first buffer separately since it's not full. */ + lastused = strcache->end - strcache->buffer; + lastfree = strcache->bytesfree; + + for (sp = strcache->next; sp != NULL; sp = sp->next) + { + int bf = sp->bytesfree; + int sz = sp->end - sp->buffer; - ++numbuffs; - numstrs += sp->count; + ++numbuffs; + numstrs += sp->count; - totsize += sz; - maxsize = (sz > maxsize ? sz : maxsize); - minsize = (sz < minsize ? sz : minsize); + totsize += sz; + maxsize = (sz > maxsize ? sz : maxsize); + minsize = (sz < minsize ? sz : minsize); - totfree += bf; - maxfree = (bf > maxfree ? bf : maxfree); - minfree = (bf < minfree ? bf : minfree); + totfree += bf; + maxfree = (bf > maxfree ? bf : maxfree); + minfree = (bf < minfree ? bf : minfree); + } } avgsize = numbuffs ? (int)(totsize / numbuffs) : 0; avgfree = numbuffs ? (int)(totfree / numbuffs) : 0; - printf (_("\n%s # of strings in strcache: %d\n"), prefix, numstrs); - printf (_("%s # of strcache buffers: %d\n"), prefix, numbuffs); - printf (_("%s strcache size: total = %d / max = %d / min = %d / avg = %d\n"), - prefix, totsize, maxsize, minsize, avgsize); - printf (_("%s strcache free: total = %d / max = %d / min = %d / avg = %d\n"), - prefix, totfree, maxfree, minfree, avgfree); + printf (_("\n%s # of strings in strcache: %d / lookups = %lu / hits = %lu\n"), + prefix, numstrs, total_adds, (total_adds - numstrs)); + printf (_("%s # of strcache buffers: %d (* %d B/buffer = %d B)\n"), + prefix, (numbuffs + 1), bufsize, ((numbuffs + 1) * bufsize)); + printf (_("%s strcache used: total = %d (%d) / max = %d / min = %d / avg = %d\n"), + prefix, totsize, lastused, maxsize, minsize, avgsize); + printf (_("%s strcache free: total = %d (%d) / max = %d / min = %d / avg = %d\n"), + prefix, totfree, lastfree, maxfree, minfree, avgfree); + + fputs (_("\n# strcache hash-table stats:\n# "), stdout); + hash_print_stats (&strings, stdout); } |