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[core] array a->sorted[] as ptrs rather than pos 

While slightly more memory use in 64-bit (though same memory use as
prior versions of lighttpd), avoids bouncing through second array
when searching in sorted list.  Most use of arrays in lighttpd is to
build a list once, and elements are not removed from the list.
personal/stbuehler/ci-build
Glenn Strauss 2019-10-15 22:45:30 -04:00
parent a762402da5
commit e3dc34d142
5 changed files with 51 additions and 49 deletions
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75
src/array.c
View File

@ -88,7 +88,7 @@ data_unset *array_pop(array * const a) {
a->used --;
du = a->data[a->used];
force_assert(a->sorted[a->used] == a->used); /* only works on "simple" lists */
force_assert(a->sorted[a->used] == du); /* only works on "simple" lists */
a->data[a->used] = NULL;
return du;
@ -117,7 +117,7 @@ static int array_keycmp(const char * const a, const size_t alen, const char * co
return alen < blen ? -1 : alen > blen ? 1 : array_caseless_compare(a, b, blen);
}
/* returns pos into a->sorted[] which contains index to data in a->data[]
/* returns pos into a->sorted[] which contains copy of data (ptr) in a->data[]
* if pos >= 0, or returns -pos-1 if that is the position-1 in a->sorted[]
* where the key needs to be inserted (-1 to avoid -0)
*/
@ -130,7 +130,7 @@ static int32_t array_get_index(const array * const a, const char * const k, cons
uint32_t lower = 0, upper = a->used;
while (lower != upper) {
uint32_t probe = (lower + upper) / 2;
const buffer * const b = &a->data[a->sorted[probe]]->key;
const buffer * const b = &a->sorted[probe]->key;
/* key is non-empty (0==b->used), though possibly blank (1==b->used),
* if inserted into key-value array */
/*force_assert(b && b->used);*/
@ -150,42 +150,34 @@ static int32_t array_get_index(const array * const a, const char * const k, cons
__attribute_hot__
data_unset *array_get_element_klen(const array * const a, const char *key, const size_t klen) {
const int32_t ipos = array_get_index(a, key, klen);
return ipos >= 0 ? a->data[a->sorted[ipos]] : NULL;
return ipos >= 0 ? a->sorted[ipos] : NULL;
}
/* non-const (data_config *) for configparser.y (not array_get_element_klen())*/
data_unset *array_get_data_unset(const array * const a, const char *key, const size_t klen) {
const int32_t ipos = array_get_index(a, key, klen);
return ipos >= 0 ? a->data[a->sorted[ipos]] : NULL;
return ipos >= 0 ? a->sorted[ipos] : NULL;
}
data_unset *array_extract_element_klen(array * const a, const char *key, const size_t klen) {
const int32_t ipos = array_get_index(a, key, klen);
if (ipos < 0) return NULL;
/* remove entry from a->sorted: move everything after pos one step left */
data_unset * const entry = a->sorted[ipos];
const uint32_t last_ndx = --a->used;
const uint32_t ndx = a->sorted[ipos], pos = (uint32_t)ipos;
data_unset * const entry = a->data[ndx];
/* now we need to swap it with the last element (if it isn't already the last element) */
if (ndx != last_ndx) {
/* to swap we also need to modify the index in a->sorted - find pos of last_elem there */
int32_t last_elem_pos = array_get_index(a, CONST_BUF_LEN(&a->data[last_ndx]->key));
/* last element must be present at the expected position */
force_assert(last_ndx == a->sorted[last_elem_pos]);
/* move entry from last_ndx to ndx */
a->data[ndx] = a->data[last_ndx];
/* fix index entry for moved entry */
a->sorted[last_elem_pos] = ndx;
}
/* remove entry in a->sorted: move everything after pos one step to the left */
if (pos != last_ndx) {
memmove(a->sorted + pos, a->sorted + pos + 1, (last_ndx - pos) * sizeof(*a->sorted));
}
if (last_ndx != (uint32_t)ipos) {
data_unset ** const d = a->sorted + ipos;
memmove(d, d+1, (last_ndx - (uint32_t)ipos) * sizeof(*d));
}
if (entry != a->data[last_ndx]) {
/* walk a->data[] to find data ptr */
/* (not checking (ndx <= last_ndx) since entry must be in a->data[]) */
uint32_t ndx = 0;
while (entry != a->data[ndx]) ++ndx;
a->data[ndx] = a->data[last_ndx]; /* swap with last element */
}
a->data[last_ndx] = NULL;
return entry;
}
@ -233,9 +225,10 @@ static void array_insert_data_at_pos(array * const a, data_unset * const entry,
/* move everything one step to the right */
if (pos != ndx) {
memmove(a->sorted + (pos + 1), a->sorted + (pos), (ndx - pos) * sizeof(*a->sorted));
data_unset ** const d = a->sorted + pos;
memmove(d+1, d, (ndx - pos) * sizeof(*a->sorted));
}
a->sorted[pos] = ndx;
a->sorted[pos] = entry;
if (prev) prev->fn->free(prev); /* free prior data, if any, from slot */
}
@ -260,7 +253,7 @@ static data_string * array_insert_string_at_pos(array * const a, const uint32_t
int * array_get_int_ptr(array * const a, const char * const k, const size_t klen) {
int32_t ipos = array_get_index(a, k, klen);
if (ipos >= 0) return &((data_integer *)a->data[a->sorted[ipos]])->value;
if (ipos >= 0) return &((data_integer *)a->sorted[ipos])->value;
data_integer * const di =array_insert_integer_at_pos(a,(uint32_t)(-ipos-1));
buffer_copy_string_len(&di->key, k, klen);
@ -270,7 +263,7 @@ int * array_get_int_ptr(array * const a, const char * const k, const size_t klen
buffer * array_get_buf_ptr(array * const a, const char * const k, const size_t klen) {
int32_t ipos = array_get_index(a, k, klen);
if (ipos >= 0) return &((data_string *)a->data[a->sorted[ipos]])->value;
if (ipos >= 0) return &((data_string *)a->sorted[ipos])->value;
data_string * const ds = array_insert_string_at_pos(a, (uint32_t)(-ipos-1));
buffer_copy_string_len(&ds->key, k, klen);
@ -297,7 +290,7 @@ static data_unset **array_find_or_insert(array * const a, data_unset * const ent
/* try to find the entry */
const int32_t ipos = array_get_index(a, CONST_BUF_LEN(&entry->key));
if (ipos >= 0) return &a->data[a->sorted[ipos]];
if (ipos >= 0) return &a->sorted[ipos];
array_insert_data_at_pos(a, entry, (uint32_t)(-ipos - 1));
return NULL;
@ -305,13 +298,21 @@ static data_unset **array_find_or_insert(array * const a, data_unset * const ent
/* replace or insert data (free existing entry) */
void array_replace(array * const a, data_unset * const entry) {
data_unset **old;
if (NULL == array_find_or_insert(a, entry)) return;
if (NULL != (old = array_find_or_insert(a, entry))) {
force_assert(*old != entry);
(*old)->fn->free(*old);
*old = entry;
}
/* find the entry (array_find_or_insert() returned non-NULL) */
const int32_t ipos = array_get_index(a, CONST_BUF_LEN(&entry->key));
force_assert(ipos >= 0);
data_unset *old = a->sorted[ipos];
force_assert(old != entry);
a->sorted[ipos] = entry;
uint32_t i = 0;
while (i < a->used && a->data[i] != old) ++i;
force_assert(i != a->used);
a->data[i] = entry;
old->fn->free(old);
}
void array_insert_unique(array * const a, data_unset * const entry) {

5
src/array.h
View File

@ -24,9 +24,8 @@ typedef struct data_unset {
} data_unset;
typedef struct {
data_unset **data;
uint32_t *sorted;
data_unset **data;
data_unset **sorted;
uint32_t used; /* <= INT32_MAX */
uint32_t size;

10
src/mod_alias.c
View File

@ -99,9 +99,9 @@ SETDEFAULTS_FUNC(mod_alias_set_defaults) {
size_t j, k;
for (j = 0; j < a->used; j ++) {
const buffer *prefix = &a->data[a->sorted[j]]->key;
const buffer *prefix = &a->sorted[j]->key;
for (k = j + 1; k < a->used; k ++) {
const buffer *key = &a->data[a->sorted[k]]->key;
const buffer *key = &a->sorted[k]->key;
if (buffer_string_length(key) < buffer_string_length(prefix)) {
break;
@ -110,7 +110,11 @@ SETDEFAULTS_FUNC(mod_alias_set_defaults) {
break;
}
/* ok, they have same prefix. check position */
if (a->sorted[j] < a->sorted[k]) {
const data_unset *dj = a->sorted[j];
const data_unset *dk = a->sorted[k];
const data_unset **data = (const data_unset **)a->data;
while (*data != dj && *data != dk) ++data;
if (*data == dj) {
log_error_write(srv, __FILE__, __LINE__, "SBSBS",
"url.alias: `", key, "' will never match as `", prefix, "' matched first");
return HANDLER_ERROR;

4
src/mod_ssi.c
View File

@ -742,7 +742,7 @@ static int process_ssi_stmt(server *srv, connection *con, handler_ctx *p, const
b = srv->tmp_buf;
buffer_clear(b);
for (i = 0; i < p->ssi_vars->used; i++) {
data_string *ds = (data_string *)p->ssi_vars->data[p->ssi_vars->sorted[i]];
data_string *ds = (data_string *)p->ssi_vars->sorted[i];
buffer_append_string_buffer(b, &ds->key);
buffer_append_string_len(b, CONST_STR_LEN("="));
@ -750,7 +750,7 @@ static int process_ssi_stmt(server *srv, connection *con, handler_ctx *p, const
buffer_append_string_len(b, CONST_STR_LEN("\n"));
}
for (i = 0; i < p->ssi_cgi_env->used; i++) {
data_string *ds = (data_string *)p->ssi_cgi_env->data[p->ssi_cgi_env->sorted[i]];
data_string *ds = (data_string *)p->ssi_cgi_env->sorted[i];
buffer_append_string_buffer(b, &ds->key);
buffer_append_string_len(b, CONST_STR_LEN("="));

6
src/mod_status.c
View File

@ -753,11 +753,9 @@ static handler_t mod_status_handle_server_statistics(server *srv, connection *co
b = chunkqueue_append_buffer_open(con->write_queue);
for (i = 0; i < st->used; i++) {
size_t ndx = st->sorted[i];
buffer_append_string_buffer(b, &st->data[ndx]->key);
buffer_append_string_buffer(b, &st->sorted[i]->key);
buffer_append_string_len(b, CONST_STR_LEN(": "));
buffer_append_int(b, ((data_integer *)(st->data[ndx]))->value);
buffer_append_int(b, ((data_integer *)st->sorted[i])->value);
buffer_append_string_len(b, CONST_STR_LEN("\n"));
}
chunkqueue_append_buffer_commit(con->write_queue);