pkgconf/libpkgconf/queue.c

329 lines
9.6 KiB
C

/*
* queue.c
* compilation of a list of packages into a world dependency set
*
* Copyright (c) 2012 pkgconf authors (see AUTHORS).
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* This software is provided 'as is' and without any warranty, express or
* implied. In no event shall the authors be liable for any damages arising
* from the use of this software.
*/
#include <libpkgconf/stdinc.h>
#include <libpkgconf/libpkgconf.h>
/*
* !doc
*
* libpkgconf `queue` module
* =========================
*
* The `queue` module provides an interface that allows easily building a dependency graph from an
* arbitrary set of dependencies. It also provides support for doing "preflight" checks on the entire
* dependency graph prior to working with it.
*
* Using the `queue` module functions is the recommended way of working with dependency graphs.
*/
typedef struct {
pkgconf_node_t iter;
char *package;
} pkgconf_queue_t;
/*
* !doc
*
* .. c:function:: void pkgconf_queue_push(pkgconf_list_t *list, const char *package)
*
* Pushes a requested dependency onto the dependency resolver's queue.
*
* :param pkgconf_list_t* list: the dependency resolution queue to add the package request to.
* :param char* package: the dependency atom requested
* :return: nothing
*/
void
pkgconf_queue_push(pkgconf_list_t *list, const char *package)
{
pkgconf_queue_t *pkgq = calloc(sizeof(pkgconf_queue_t), 1);
pkgq->package = strdup(package);
pkgconf_node_insert(&pkgq->iter, pkgq, list);
}
/*
* !doc
*
* .. c:function:: bool pkgconf_queue_compile(pkgconf_client_t *client, pkgconf_pkg_t *world, pkgconf_list_t *list)
*
* Compile a dependency resolution queue into a dependency resolution problem if possible, otherwise report an error.
*
* :param pkgconf_client_t* client: The pkgconf client object to use for dependency resolution.
* :param pkgconf_pkg_t* world: The designated root of the dependency graph.
* :param pkgconf_list_t* list: The list of dependency requests to consider.
* :return: true if the built dependency resolution problem is consistent, else false
* :rtype: bool
*/
bool
pkgconf_queue_compile(pkgconf_client_t *client, pkgconf_pkg_t *world, pkgconf_list_t *list)
{
pkgconf_node_t *iter;
PKGCONF_FOREACH_LIST_ENTRY(list->head, iter)
{
pkgconf_queue_t *pkgq;
pkgq = iter->data;
pkgconf_dependency_parse(client, world, &world->required, pkgq->package, 0);
}
return (world->required.head != NULL);
}
/*
* !doc
*
* .. c:function:: void pkgconf_queue_free(pkgconf_list_t *list)
*
* Release any memory related to a dependency resolution queue.
*
* :param pkgconf_list_t* list: The dependency resolution queue to release.
* :return: nothing
*/
void
pkgconf_queue_free(pkgconf_list_t *list)
{
pkgconf_node_t *node, *tnode;
PKGCONF_FOREACH_LIST_ENTRY_SAFE(list->head, tnode, node)
{
pkgconf_queue_t *pkgq = node->data;
free(pkgq->package);
free(pkgq);
}
}
static void
pkgconf_queue_collect_dependents(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data)
{
pkgconf_node_t *node;
pkgconf_pkg_t *world = data;
if (pkg == world)
return;
PKGCONF_FOREACH_LIST_ENTRY(pkg->required.head, node)
{
pkgconf_dependency_t *flattened_dep;
flattened_dep = pkgconf_dependency_copy(client, node->data);
pkgconf_node_insert(&flattened_dep->iter, flattened_dep, &world->required);
}
PKGCONF_FOREACH_LIST_ENTRY(pkg->requires_private.head, node)
{
pkgconf_dependency_t *flattened_dep;
flattened_dep = pkgconf_dependency_copy(client, node->data);
pkgconf_node_insert(&flattened_dep->iter, flattened_dep, &world->requires_private);
}
}
static int
dep_sort_cmp(const void *a, const void *b)
{
const pkgconf_dependency_t *depA = *(void **) a;
const pkgconf_dependency_t *depB = *(void **) b;
return depB->match->hits - depA->match->hits;
}
static inline void
flatten_dependency_set(pkgconf_client_t *client, pkgconf_list_t *list)
{
pkgconf_node_t *node, *next;
pkgconf_dependency_t **deps = NULL;
size_t dep_count = 0, i;
PKGCONF_FOREACH_LIST_ENTRY_SAFE(list->head, next, node)
{
pkgconf_dependency_t *dep = node->data;
pkgconf_pkg_t *pkg = pkgconf_pkg_verify_dependency(client, dep, NULL);
if (pkg == NULL)
continue;
if (pkg->serial == client->serial)
{
PKGCONF_TRACE(client, "dedup %s serials match", pkg->id);
pkgconf_dependency_unref(dep->owner, dep);
goto next;
}
if (dep->match == NULL)
{
PKGCONF_TRACE(client, "WTF: unmatched dependency %p <%s>", dep, dep->package);
abort();
}
/* for virtuals, we need to check to see if there are dupes */
for (i = 0; i < dep_count; i++)
{
pkgconf_dependency_t *other_dep = deps[i];
PKGCONF_TRACE(client, "dedup %s = %s?", dep->package, other_dep->package);
if (!strcmp(dep->package, other_dep->package))
{
PKGCONF_TRACE(client, "skipping, %zu deps", dep_count);
pkgconf_dependency_unref(dep->owner, dep);
goto next;
}
}
pkg->serial = client->serial;
/* copy to the deps table */
dep_count++;
deps = pkgconf_reallocarray(deps, dep_count, sizeof (void *));
deps[dep_count - 1] = dep;
PKGCONF_TRACE(client, "added %s to dep table", dep->package);
next:
pkgconf_pkg_unref(client, pkg);
}
qsort(deps, dep_count, sizeof (void *), dep_sort_cmp);
/* zero the list and start readding */
pkgconf_list_zero(list);
for (i = 0; i < dep_count; i++)
{
pkgconf_dependency_t *dep = deps[i];
memset(&dep->iter, '\0', sizeof (dep->iter));
pkgconf_node_insert(&dep->iter, dep, list);
PKGCONF_TRACE(client, "slot %zu: dep %s matched to %p<%s> hits %lu", i, dep->package, dep->match, dep->match == NULL ? "NULL" : dep->match->id, dep->match->hits);
}
free(deps);
}
static inline unsigned int
pkgconf_queue_verify(pkgconf_client_t *client, pkgconf_pkg_t *world, pkgconf_list_t *list, int maxdepth)
{
unsigned int result;
if (!pkgconf_queue_compile(client, world, list))
return PKGCONF_PKG_ERRF_DEPGRAPH_BREAK;
/* collect all the dependencies */
result = pkgconf_pkg_traverse(client, world, pkgconf_queue_collect_dependents, world, maxdepth, 0);
if (result != PKGCONF_PKG_ERRF_OK)
return result;
/* flatten the dependency set using serials.
* we copy the dependencies to a vector, and then erase the list.
* then we copy them back to the list.
*/
++client->serial;
PKGCONF_TRACE(client, "flattening requires deps");
flatten_dependency_set(client, &world->required);
++client->serial;
PKGCONF_TRACE(client, "flattening requires.private deps");
flatten_dependency_set(client, &world->requires_private);
return PKGCONF_PKG_ERRF_OK;
}
/*
* !doc
*
* .. c:function:: void pkgconf_queue_apply(pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_queue_apply_func_t func, int maxdepth, void *data)
*
* Attempt to compile a dependency resolution queue into a dependency resolution problem, then attempt to solve the problem and
* feed the solution to a callback function if a complete dependency graph is found.
*
* :param pkgconf_client_t* client: The pkgconf client object to use for dependency resolution.
* :param pkgconf_list_t* list: The list of dependency requests to consider.
* :param pkgconf_queue_apply_func_t func: The callback function to call if a solution is found by the dependency resolver.
* :param int maxdepth: The maximum allowed depth for the dependency resolver. A depth of -1 means unlimited.
* :param void* data: An opaque pointer which is passed to the callback function.
* :returns: true if the dependency resolver found a solution, otherwise false.
* :rtype: bool
*/
bool
pkgconf_queue_apply(pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_queue_apply_func_t func, int maxdepth, void *data)
{
pkgconf_pkg_t world = {
.id = "virtual:world",
.realname = "virtual world package",
.flags = PKGCONF_PKG_PROPF_STATIC | PKGCONF_PKG_PROPF_VIRTUAL,
};
/* if maxdepth is one, then we will not traverse deeper than our virtual package. */
if (!maxdepth)
maxdepth = -1;
if (pkgconf_queue_verify(client, &world, list, maxdepth) != PKGCONF_PKG_ERRF_OK)
return false;
/* the world dependency set is flattened after it is returned from pkgconf_queue_verify */
if (!func(client, &world, data, maxdepth))
{
pkgconf_pkg_free(client, &world);
return false;
}
pkgconf_pkg_free(client, &world);
return true;
}
/*
* !doc
*
* .. c:function:: void pkgconf_queue_validate(pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_queue_apply_func_t func, int maxdepth, void *data)
*
* Attempt to compile a dependency resolution queue into a dependency resolution problem, then attempt to solve the problem.
*
* :param pkgconf_client_t* client: The pkgconf client object to use for dependency resolution.
* :param pkgconf_list_t* list: The list of dependency requests to consider.
* :param int maxdepth: The maximum allowed depth for the dependency resolver. A depth of -1 means unlimited.
* :returns: true if the dependency resolver found a solution, otherwise false.
* :rtype: bool
*/
bool
pkgconf_queue_validate(pkgconf_client_t *client, pkgconf_list_t *list, int maxdepth)
{
bool retval = true;
pkgconf_pkg_t world = {
.id = "virtual:world",
.realname = "virtual world package",
.flags = PKGCONF_PKG_PROPF_STATIC | PKGCONF_PKG_PROPF_VIRTUAL,
};
/* if maxdepth is one, then we will not traverse deeper than our virtual package. */
if (!maxdepth)
maxdepth = -1;
if (pkgconf_queue_verify(client, &world, list, maxdepth) != PKGCONF_PKG_ERRF_OK)
retval = false;
pkgconf_pkg_free(client, &world);
return retval;
}