A really faster dependency sorting algorithm, 60% faster approx!

Benchmarks before and after the code for installing
"xorg gnome xbmc vlc firefox epdfview":

OLD
-----------------
real	0m1.844s
user	0m1.841s
sys	0m0.003s

NEW
-----------------
real	0m0.873s
user	0m0.868s
sys	0m0.004s
This commit is contained in:
Juan RP 2011-01-28 19:47:05 +01:00
parent 03b1b254cc
commit 6e26332a2e

View File

@ -30,36 +30,227 @@
#include <xbps_api.h>
#include "xbps_api_impl.h"
#include "queue.h"
#include "strlcpy.h"
/*
* Sorting algorithm for packages in the transaction dictionary.
* The transaction dictionary contains all package dictionaries found from
* the repository plist index file in the "unsorted_deps" array.
*
* When a package has no rundeps or all rundeps are satisfied, the package
* dictionary is added into the sorted "packages" array and it is marked as
* sorted in its dictionary with a boolean object.
* Any package in the unsorted_deps array is added into the tail and
* later if a package dependency has an index greater than current
* package, the package dependency is moved just before it.
*
* It will loop until all packages are processed and will check that
* the number of packages added into the "packages" array is the same than
* it was in the "unsorted_deps" array.
*
* Sure I could make it not iterate so many times but probably it will
* also be slower! that's why XBPS uses proplib with its red-black trees,
* iterating over them is fast.
* Once that all package dependencies for a package are in the correct
* index, the counter is increased. When all packages in the "unsorted_deps"
* array are processed the loop is stopped and the counter should have
* the same number than the "unsorted_deps" array... otherwise something
* went wrong.
*/
struct pkgdep {
TAILQ_ENTRY(pkgdep) pkgdep_entries;
prop_dictionary_t d;
char *name;
};
static TAILQ_HEAD(pkgdep_head, pkgdep) pkgdep_list =
TAILQ_HEAD_INITIALIZER(pkgdep_list);
static struct pkgdep *
pkgdep_find(const char *name)
{
struct pkgdep *pd = NULL;
TAILQ_FOREACH(pd, &pkgdep_list, pkgdep_entries)
if (strcmp(pd->name, name) == 0)
return pd;
/* not found */
return NULL;
}
static ssize_t
pkgdep_find_idx(const char *name)
{
struct pkgdep *pd;
ssize_t idx = 0;
TAILQ_FOREACH(pd, &pkgdep_list, pkgdep_entries) {
if (strcmp(pd->name, name) == 0)
return idx;
idx++;
}
/* not found */
return -1;
}
static void
pkgdep_release(struct pkgdep *pd)
{
if (pd->d != NULL)
prop_object_release(pd->d);
free(pd->name);
free(pd);
pd = NULL;
}
static struct pkgdep *
pkgdep_alloc(prop_dictionary_t d, const char *name)
{
struct pkgdep *pd;
size_t len;
if ((pd = malloc(sizeof(*pd))) == NULL)
return NULL;
len = strlen(name) + 1;
if ((pd->name = malloc(len)) == NULL) {
free(pd);
return NULL;
}
if (d != NULL)
pd->d = prop_dictionary_copy(d);
else
pd->d = NULL;
(void)strlcpy(pd->name, name, len);
return pd;
}
static void
pkgdep_end(prop_array_t sorted)
{
struct pkgdep *pd;
while ((pd = TAILQ_FIRST(&pkgdep_list)) != NULL) {
TAILQ_REMOVE(&pkgdep_list, pd, pkgdep_entries);
if (sorted != NULL && pd->d != NULL)
prop_array_add(sorted, pd->d);
pkgdep_release(pd);
}
}
static int
sort_pkg_rundeps(prop_dictionary_t transd,
struct pkgdep *pd,
prop_array_t pkg_rundeps)
{
prop_dictionary_t curpkgd;
prop_object_t obj;
struct pkgdep *lpd, *pdn;
const char *str;
char *pkgnamedep;
ssize_t pkgdepidx, curpkgidx = pkgdep_find_idx(pd->name);
size_t i, idx = 0;
int rv = 0;
xbps_dbg_printf_append("\n");
again:
for (i = idx; i < prop_array_count(pkg_rundeps); i++) {
obj = prop_array_get(pkg_rundeps, i);
str = prop_string_cstring_nocopy(obj);
if (str == NULL) {
rv = ENOMEM;
break;
}
pkgnamedep = xbps_get_pkgpattern_name(str);
if (pkgnamedep == NULL) {
rv = ENOMEM;
break;
}
xbps_dbg_printf(" Required dependency '%s': ", str);
pdn = pkgdep_find(pkgnamedep);
if ((pdn == NULL) &&
xbps_check_is_installed_pkg_by_name(pkgnamedep)) {
/*
* Package dependency is installed, just add to
* the list but just mark it as "installed", to avoid
* calling xbps_check_is_installed_pkg_by_name(),
* which is expensive.
*/
xbps_dbg_printf_append("installed.\n");
lpd = pkgdep_alloc(NULL, pkgnamedep);
if (lpd == NULL) {
rv = ENOMEM;
break;
}
free(pkgnamedep);
TAILQ_INSERT_TAIL(&pkgdep_list, lpd, pkgdep_entries);
continue;
} else if (pdn != NULL && pdn->d == NULL) {
/*
* Package was added previously into the list
* and is installed, skip.
*/
xbps_dbg_printf_append("installed.\n");
free(pkgnamedep);
continue;
}
curpkgd = xbps_find_pkg_in_dict_by_name(transd,
"unsorted_deps", pkgnamedep);
assert(curpkgd != NULL);
lpd = pkgdep_alloc(curpkgd, pkgnamedep);
if (lpd == NULL) {
free(pkgnamedep);
rv = ENOMEM;
break;
}
if (pdn == NULL) {
/*
* If package is not in the list, add to the tail
* and iterate at the same position.
*/
TAILQ_INSERT_TAIL(&pkgdep_list, lpd, pkgdep_entries);
idx = i;
xbps_dbg_printf_append("added into the tail, "
"checking again...\n");
free(pkgnamedep);
goto again;
}
/*
* Find package dependency index.
*/
pkgdepidx = pkgdep_find_idx(pkgnamedep);
/*
* If package dependency index is less than current
* package index, it's already sorted.
*/
free(pkgnamedep);
if (pkgdepidx < curpkgidx) {
xbps_dbg_printf_append("already sorted.\n");
pkgdep_release(lpd);
} else {
/*
* Remove package dependency from list and move
* it before current package.
*/
TAILQ_REMOVE(&pkgdep_list, pdn, pkgdep_entries);
pkgdep_release(pdn);
TAILQ_INSERT_BEFORE(pd, lpd, pkgdep_entries);
xbps_dbg_printf_append("added before `%s'.\n", pd->name);
}
}
return rv;
}
int HIDDEN
xbps_sort_pkg_deps(void)
{
prop_dictionary_t transd;
prop_array_t sorted, unsorted, rundeps;
prop_object_t obj, obj2;
prop_object_iterator_t iter, iter2;
size_t ndeps = 0, rundepscnt = 0, cnt = 0;
const char *pkgname, *pkgver, *str;
char *pkgnamedep;
prop_object_t obj;
prop_object_iterator_t iter;
struct pkgdep *pd;
size_t ndeps = 0, cnt = 0;
const char *pkgname, *pkgver;
int rv = 0;
bool done;
if ((transd = xbps_transaction_dictionary_get()) == NULL)
return EINVAL;
@ -97,27 +288,28 @@ xbps_sort_pkg_deps(void)
rv = ENOMEM;
goto out;
}
again:
/*
* Order all deps by looking at its run_depends array.
* Iterate over the unsorted package dictionaries and sort all
* its package dependencies.
*/
while ((obj = prop_object_iterator_next(iter)) != NULL) {
/* no more iterations required, pkglist is sorted */
if (cnt >= ndeps)
break;
prop_dictionary_get_cstring_nocopy(obj, "pkgname", &pkgname);
prop_dictionary_get_cstring_nocopy(obj, "pkgver", &pkgver);
xbps_dbg_printf("Sorting package '%s': ", pkgver);
/*
* Check if package was sorted previously and skip.
*/
done = false;
prop_dictionary_get_bool(obj, "sorted", &done);
if (done) {
xbps_dbg_printf_append("skipping, already sorted.\n",
pkgname);
continue;
pd = pkgdep_find(pkgname);
if (pd == NULL) {
/*
* If package not in list, just add to the tail.
*/
pd = pkgdep_alloc(obj, pkgname);
if (pd == NULL) {
pkgdep_end(NULL);
prop_object_iterator_release(iter);
rv = ENOMEM;
goto out;
}
TAILQ_INSERT_TAIL(&pkgdep_list, pd, pkgdep_entries);
}
/*
* Packages that don't have deps go unsorted, because
@ -127,88 +319,36 @@ again:
if (rundeps == NULL || prop_array_count(rundeps) == 0) {
xbps_dbg_printf_append("added (no rundeps) into "
"the sorted queue.\n");
prop_array_add(sorted, obj);
prop_dictionary_set_bool(obj, "sorted", true);
cnt++;
continue;
}
iter2 = prop_array_iterator(rundeps);
if (iter2 == NULL) {
rv = ENOMEM;
/*
* Sort package run-time dependencies for this package.
*/
if ((rv = sort_pkg_rundeps(transd, pd, rundeps)) != 0) {
pkgdep_end(NULL);
prop_object_iterator_release(iter);
goto out;
}
xbps_dbg_printf_append("\n");
/*
* Iterate over the run_depends array, and find out if they
* were already added in the sorted list.
*/
while ((obj2 = prop_object_iterator_next(iter2)) != NULL) {
str = prop_string_cstring_nocopy(obj2);
assert(str != NULL);
pkgnamedep = xbps_get_pkgpattern_name(str);
if (pkgnamedep == NULL) {
rv = EINVAL;
goto out;
}
xbps_dbg_printf(" Required dependency '%s': ", str);
/*
* If dependency is already satisfied or queued,
* pass to the next one.
*/
if (xbps_check_is_installed_pkg_by_name(pkgnamedep)) {
rundepscnt++;
xbps_dbg_printf_append("installed.\n");
} else if (xbps_find_pkg_in_dict_by_name(transd,
"packages", pkgnamedep)) {
xbps_dbg_printf_append("queued.\n");
rundepscnt++;
} else {
xbps_dbg_printf_append("not installed.\n");
}
free(pkgnamedep);
}
prop_object_iterator_release(iter2);
/* Add dependency if all its required deps are already added */
if (prop_array_count(rundeps) == rundepscnt) {
prop_array_add(sorted, obj);
prop_dictionary_set_bool(obj, "sorted", true);
xbps_dbg_printf("Added package '%s' to the sorted "
"queue (all rundeps satisfied).\n", pkgver);
rundepscnt = 0;
cnt++;
continue;
}
xbps_dbg_printf("Unsorted package '%s' has missing "
"rundeps (missing %zu).\n", pkgver,
prop_array_count(rundeps) - rundepscnt);
rundepscnt = 0;
}
/* Iterate until all deps are processed. */
if (cnt < ndeps) {
xbps_dbg_printf("Missing required deps! queued: %zu "
"required: %zu.\n", cnt, ndeps);
prop_object_iterator_reset(iter);
goto again;
cnt++;
}
prop_object_iterator_release(iter);
/*
* We are done, now we have to copy all pkg dictionaries
* from the sorted list into the "packages" array, and at
* the same time freeing memory used for temporary sorting.
*/
pkgdep_end(sorted);
/*
* Sanity check that the array contains the same number of
* objects than the total number of required dependencies.
*/
if (ndeps != prop_array_count(sorted)) {
xbps_dbg_printf("wrong sorted deps cnt %zu vs %zu\n",
ndeps, prop_array_count(sorted));
rv = EINVAL;
goto out;
}
assert(cnt == prop_array_count(unsorted));
/*
* We are done, all packages were sorted... remove the
* temporary array with unsorted packages.
*/
prop_dictionary_remove(transd, "unsorted_deps");
out:
if (rv != 0)
prop_dictionary_remove(transd, "packages");