pacman/lib/libalpm/sync.c

/*
 *  sync.c
 *
 *  Copyright (c) 2006-2011 Pacman Development Team <pacman-dev@archlinux.org>
 *  Copyright (c) 2002-2006 by Judd Vinet <jvinet@zeroflux.org>
 *  Copyright (c) 2005 by Aurelien Foret <orelien@chez.com>
 *  Copyright (c) 2005 by Christian Hamar <krics@linuxforum.hu>
 *  Copyright (c) 2005, 2006 by Miklos Vajna <vmiklos@frugalware.org>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <sys/types.h> /* off_t */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h> /* intmax_t */
#include <unistd.h>
#include <limits.h>

/* libalpm */
#include "sync.h"
#include "alpm_list.h"
#include "log.h"
#include "package.h"
#include "db.h"
#include "deps.h"
#include "conflict.h"
#include "trans.h"
#include "add.h"
#include "util.h"
#include "handle.h"
#include "alpm.h"
#include "dload.h"
#include "delta.h"
#include "remove.h"
#include "diskspace.h"
#include "signing.h"

/** Check for new version of pkg in sync repos
 * (only the first occurrence is considered in sync)
 */
alpm_pkg_t SYMEXPORT *alpm_sync_newversion(alpm_pkg_t *pkg, alpm_list_t *dbs_sync)
{
	alpm_list_t *i;
	alpm_pkg_t *spkg = NULL;

	ASSERT(pkg != NULL, return NULL);
	pkg->handle->pm_errno = 0;

	for(i = dbs_sync; !spkg && i; i = i->next) {
		spkg = _alpm_db_get_pkgfromcache(i->data, pkg->name);
	}

	if(spkg == NULL) {
		_alpm_log(pkg->handle, ALPM_LOG_DEBUG, "'%s' not found in sync db => no upgrade\n",
				pkg->name);
		return NULL;
	}

	/* compare versions and see if spkg is an upgrade */
	if(_alpm_pkg_compare_versions(spkg, pkg) > 0) {
		_alpm_log(pkg->handle, ALPM_LOG_DEBUG, "new version of '%s' found (%s => %s)\n",
					pkg->name, pkg->version, spkg->version);
		return spkg;
	}
	/* spkg is not an upgrade */
	return NULL;
}

static int check_literal(alpm_handle_t *handle, alpm_pkg_t *lpkg,
		alpm_pkg_t *spkg, int enable_downgrade)
{
	/* 1. literal was found in sdb */
	int cmp = _alpm_pkg_compare_versions(spkg, lpkg);
	if(cmp > 0) {
		_alpm_log(handle, ALPM_LOG_DEBUG, "new version of '%s' found (%s => %s)\n",
				lpkg->name, lpkg->version, spkg->version);
		/* check IgnorePkg/IgnoreGroup */
		if(_alpm_pkg_should_ignore(handle, spkg)
				|| _alpm_pkg_should_ignore(handle, lpkg)) {
			_alpm_log(handle, ALPM_LOG_WARNING, _("%s: ignoring package upgrade (%s => %s)\n"),
					lpkg->name, lpkg->version, spkg->version);
		} else {
			_alpm_log(handle, ALPM_LOG_DEBUG, "adding package %s-%s to the transaction targets\n",
					spkg->name, spkg->version);
			return 1;
		}
	} else if(cmp < 0) {
		if(enable_downgrade) {
			/* check IgnorePkg/IgnoreGroup */
			if(_alpm_pkg_should_ignore(handle, spkg)
					|| _alpm_pkg_should_ignore(handle, lpkg)) {
				_alpm_log(handle, ALPM_LOG_WARNING, _("%s: ignoring package downgrade (%s => %s)\n"),
						lpkg->name, lpkg->version, spkg->version);
			} else {
				_alpm_log(handle, ALPM_LOG_WARNING, _("%s: downgrading from version %s to version %s\n"),
						lpkg->name, lpkg->version, spkg->version);
				return 1;
			}
		} else {
			alpm_db_t *sdb = alpm_pkg_get_db(spkg);
			_alpm_log(handle, ALPM_LOG_WARNING, _("%s: local (%s) is newer than %s (%s)\n"),
					lpkg->name, lpkg->version, sdb->treename, spkg->version);
		}
	}
	return 0;
}

static alpm_list_t *check_replacers(alpm_handle_t *handle, alpm_pkg_t *lpkg,
		alpm_db_t *sdb)
{
	/* 2. search for replacers in sdb */
	alpm_list_t *replacers = NULL;
	alpm_list_t *k;
	_alpm_log(handle, ALPM_LOG_DEBUG,
			"searching for replacements for %s\n", lpkg->name);
	for(k = _alpm_db_get_pkgcache(sdb); k; k = k->next) {
		int found = 0;
		alpm_pkg_t *spkg = k->data;
		alpm_list_t *l;
		for(l = alpm_pkg_get_replaces(spkg); l; l = l->next) {
			alpm_depend_t *replace = l->data;
			/* we only want to consider literal matches at this point. */
			if(_alpm_depcmp_literal(lpkg, replace)) {
				found = 1;
				break;
			}
		}
		if(found) {
			int doreplace = 0;
			alpm_pkg_t *tpkg;
			/* check IgnorePkg/IgnoreGroup */
			if(_alpm_pkg_should_ignore(handle, spkg)
					|| _alpm_pkg_should_ignore(handle, lpkg)) {
				_alpm_log(handle, ALPM_LOG_WARNING,
						_("ignoring package replacement (%s-%s => %s-%s)\n"),
						lpkg->name, lpkg->version, spkg->name, spkg->version);
				continue;
			}

			QUESTION(handle, ALPM_QUESTION_REPLACE_PKG, lpkg, spkg,
					sdb->treename, &doreplace);
			if(!doreplace) {
				continue;
			}

			/* If spkg is already in the target list, we append lpkg to spkg's
			 * removes list */
			tpkg = _alpm_pkg_find(handle->trans->add, spkg->name);
			if(tpkg) {
				/* sanity check, multiple repos can contain spkg->name */
				if(tpkg->origin_data.db != sdb) {
					_alpm_log(handle, ALPM_LOG_WARNING, _("cannot replace %s by %s\n"),
							lpkg->name, spkg->name);
					continue;
				}
				_alpm_log(handle, ALPM_LOG_DEBUG, "appending %s to the removes list of %s\n",
						lpkg->name, tpkg->name);
				tpkg->removes = alpm_list_add(tpkg->removes, lpkg);
				/* check the to-be-replaced package's reason field */
				if(alpm_pkg_get_reason(lpkg) == ALPM_PKG_REASON_EXPLICIT) {
					tpkg->reason = ALPM_PKG_REASON_EXPLICIT;
				}
			} else {
				/* add spkg to the target list */
				/* copy over reason */
				spkg->reason = alpm_pkg_get_reason(lpkg);
				spkg->removes = alpm_list_add(NULL, lpkg);
				_alpm_log(handle, ALPM_LOG_DEBUG,
						"adding package %s-%s to the transaction targets\n",
						spkg->name, spkg->version);
				replacers = alpm_list_add(replacers, spkg);
			}
		}
	}
	return replacers;
}

/** Search for packages to upgrade and add them to the transaction. */
int SYMEXPORT alpm_sync_sysupgrade(alpm_handle_t *handle, int enable_downgrade)
{
	alpm_list_t *i, *j;
	alpm_trans_t *trans;

	CHECK_HANDLE(handle, return -1);
	trans = handle->trans;
	ASSERT(trans != NULL, RET_ERR(handle, ALPM_ERR_TRANS_NULL, -1));
	ASSERT(trans->state == STATE_INITIALIZED, RET_ERR(handle, ALPM_ERR_TRANS_NOT_INITIALIZED, -1));

	_alpm_log(handle, ALPM_LOG_DEBUG, "checking for package upgrades\n");
	for(i = _alpm_db_get_pkgcache(handle->db_local); i; i = i->next) {
		alpm_pkg_t *lpkg = i->data;

		if(_alpm_pkg_find(trans->add, lpkg->name)) {
			_alpm_log(handle, ALPM_LOG_DEBUG, "%s is already in the target list -- skipping\n", lpkg->name);
			continue;
		}

		/* Search for literal then replacers in each sync database. */
		for(j = handle->dbs_sync; j; j = j->next) {
			alpm_db_t *sdb = j->data;
			/* Check sdb */
			alpm_pkg_t *spkg = _alpm_db_get_pkgfromcache(sdb, lpkg->name);
			int literal_upgrade = 0;
			if(spkg) {
				literal_upgrade = check_literal(handle, lpkg, spkg, enable_downgrade);
				if(literal_upgrade) {
					trans->add = alpm_list_add(trans->add, spkg);
				}
				/* jump to next local package */
				break;
			} else {
				alpm_list_t *replacers;
				replacers = check_replacers(handle, lpkg, sdb);
				if(replacers) {
					trans->add = alpm_list_join(trans->add, replacers);
				}
			}
		}
	}

	return 0;
}

/** Find group members across a list of databases.
 * If a member exists in several databases, only the first database is used.
 * IgnorePkg is also handled.
 * @param dbs the list of alpm_db_t *
 * @param name the name of the group
 * @return the list of alpm_pkg_t * (caller is responsible for alpm_list_free)
 */
alpm_list_t SYMEXPORT *alpm_find_group_pkgs(alpm_list_t *dbs,
		const char *name)
{
	alpm_list_t *i, *j, *pkgs = NULL, *ignorelist = NULL;

	for(i = dbs; i; i = i->next) {
		alpm_db_t *db = i->data;
		alpm_group_t *grp = alpm_db_readgroup(db, name);

		if(!grp)
			continue;

		for(j = grp->packages; j; j = j->next) {
			alpm_pkg_t *pkg = j->data;

			if(_alpm_pkg_find(ignorelist, pkg->name)) {
				continue;
			}
			if(_alpm_pkg_should_ignore(db->handle, pkg)) {
				ignorelist = alpm_list_add(ignorelist, pkg);
				int install = 0;
				QUESTION(db->handle, ALPM_QUESTION_INSTALL_IGNOREPKG, pkg,
						NULL, NULL, &install);
				if(!install)
					continue;
			}
			if(!_alpm_pkg_find(pkgs, pkg->name)) {
				pkgs = alpm_list_add(pkgs, pkg);
			}
		}
	}
	alpm_list_free(ignorelist);
	return pkgs;
}

/** Compute the size of the files that will be downloaded to install a
 * package.
 * @param newpkg the new package to upgrade to
 */
static int compute_download_size(alpm_pkg_t *newpkg)
{
	const char *fname;
	char *fpath, *fnamepart = NULL;
	off_t size = 0;
	alpm_handle_t *handle = newpkg->handle;

	if(newpkg->origin != PKG_FROM_SYNCDB) {
		newpkg->infolevel |= INFRQ_DSIZE;
		newpkg->download_size = 0;
		return 0;
	}

	ASSERT(newpkg->filename != NULL, RET_ERR(handle, ALPM_ERR_PKG_INVALID_NAME, -1));
	fname = newpkg->filename;
	fpath = _alpm_filecache_find(handle, fname);

	/* downloaded file exists, so there's nothing to grab */
	if(fpath) {
		size = 0;
		goto finish;
	}

	CALLOC(fnamepart, strlen(fname) + 6, sizeof(char), return -1);
	sprintf(fnamepart, "%s.part", fname);
	fpath = _alpm_filecache_find(handle, fnamepart);
	if(fpath) {
		struct stat st;
		if(stat(fpath, &st) == 0) {
			/* subtract the size of the .part file */
			_alpm_log(handle, ALPM_LOG_DEBUG, "using (package - .part) size\n");
			size = newpkg->size - st.st_size;
			size = size < 0 ? 0 : size;
		}
	} else if(handle->usedelta) {
		off_t dltsize;

		dltsize = _alpm_shortest_delta_path(handle, newpkg->deltas,
				newpkg->filename, &newpkg->delta_path);

		if(newpkg->delta_path && (dltsize < newpkg->size * MAX_DELTA_RATIO)) {
			_alpm_log(handle, ALPM_LOG_DEBUG, "using delta size\n");
			size = dltsize;
		} else {
			_alpm_log(handle, ALPM_LOG_DEBUG, "using package size\n");
			size = newpkg->size;
			alpm_list_free(newpkg->delta_path);
			newpkg->delta_path = NULL;
		}
	} else {
		size = newpkg->size;
	}

finish:
	_alpm_log(handle, ALPM_LOG_DEBUG, "setting download size %jd for pkg %s\n",
			(intmax_t)size, newpkg->name);

	newpkg->infolevel |= INFRQ_DSIZE;
	newpkg->download_size = size;

	FREE(fpath);
	FREE(fnamepart);

	return 0;
}

int _alpm_sync_prepare(alpm_handle_t *handle, alpm_list_t **data)
{
	alpm_list_t *i, *j;
	alpm_list_t *deps = NULL;
	alpm_list_t *unresolvable = NULL;
	alpm_list_t *remove = NULL;
	int ret = 0;
	alpm_trans_t *trans = handle->trans;

	if(data) {
		*data = NULL;
	}

	/* ensure all sync database are valid since we will be using them */
	for(i = handle->dbs_sync; i; i = i->next) {
		const alpm_db_t *db = i->data;
		if(db->status & DB_STATUS_INVALID) {
			RET_ERR(handle, ALPM_ERR_DB_INVALID, -1);
		}
		if(db->status & DB_STATUS_MISSING) {
			RET_ERR(handle, ALPM_ERR_DB_NOT_FOUND, -1);
		}
	}

	if(!(trans->flags & ALPM_TRANS_FLAG_NODEPS)) {
		alpm_list_t *resolved = NULL; /* target list after resolvedeps */

		/* Build up list by repeatedly resolving each transaction package */
		/* Resolve targets dependencies */
		EVENT(handle, ALPM_EVENT_RESOLVEDEPS_START, NULL, NULL);
		_alpm_log(handle, ALPM_LOG_DEBUG, "resolving target's dependencies\n");

		/* build remove list for resolvedeps */
		for(i = trans->add; i; i = i->next) {
			alpm_pkg_t *spkg = i->data;
			for(j = spkg->removes; j; j = j->next) {
				remove = alpm_list_add(remove, j->data);
			}
		}

		/* Compute the fake local database for resolvedeps (partial fix for the
		 * phonon/qt issue) */
		alpm_list_t *localpkgs = alpm_list_diff(_alpm_db_get_pkgcache(handle->db_local),
				trans->add, _alpm_pkg_cmp);

		/* Resolve packages in the transaction one at a time, in addition
		   building up a list of packages which could not be resolved. */
		for(i = trans->add; i; i = i->next) {
			alpm_pkg_t *pkg = i->data;
			if(_alpm_resolvedeps(handle, localpkgs, pkg, trans->add,
						&resolved, remove, data) == -1) {
				unresolvable = alpm_list_add(unresolvable, pkg);
			}
			/* Else, [resolved] now additionally contains [pkg] and all of its
			   dependencies not already on the list */
		}
		alpm_list_free(localpkgs);

		/* If there were unresolvable top-level packages, prompt the user to
		   see if they'd like to ignore them rather than failing the sync */
		if(unresolvable != NULL) {
			int remove_unresolvable = 0;
			QUESTION(handle, ALPM_QUESTION_REMOVE_PKGS, unresolvable,
					NULL, NULL, &remove_unresolvable);
			if(remove_unresolvable) {
				/* User wants to remove the unresolvable packages from the
				   transaction. The packages will be removed from the actual
				   transaction when the transaction packages are replaced with a
				   dependency-reordered list below */
				handle->pm_errno = 0; /* pm_errno was set by resolvedeps */
				if(data) {
					alpm_list_free_inner(*data, (alpm_list_fn_free)_alpm_depmiss_free);
					alpm_list_free(*data);
					*data = NULL;
				}
			} else {
				/* pm_errno is set by resolvedeps */
				alpm_list_free(resolved);
				ret = -1;
				goto cleanup;
			}
		}

		/* Set DEPEND reason for pulled packages */
		for(i = resolved; i; i = i->next) {
			alpm_pkg_t *pkg = i->data;
			if(!_alpm_pkg_find(trans->add, pkg->name)) {
				pkg->reason = ALPM_PKG_REASON_DEPEND;
			}
		}

		/* Unresolvable packages will be removed from the target list; set these
		 * aside in the transaction as a list we won't operate on. If we free them
		 * before the end of the transaction, we may kill pointers the frontend
		 * holds to package objects. */
		trans->unresolvable = unresolvable;

		/* re-order w.r.t. dependencies */
		alpm_list_free(trans->add);
		trans->add = _alpm_sortbydeps(handle, resolved, 0);
		alpm_list_free(resolved);

		EVENT(handle, ALPM_EVENT_RESOLVEDEPS_DONE, NULL, NULL);
	}

	if(!(trans->flags & ALPM_TRANS_FLAG_NOCONFLICTS)) {
		/* check for inter-conflicts and whatnot */
		EVENT(handle, ALPM_EVENT_INTERCONFLICTS_START, NULL, NULL);

		_alpm_log(handle, ALPM_LOG_DEBUG, "looking for conflicts\n");

		/* 1. check for conflicts in the target list */
		_alpm_log(handle, ALPM_LOG_DEBUG, "check targets vs targets\n");
		deps = _alpm_innerconflicts(handle, trans->add);

		for(i = deps; i; i = i->next) {
			alpm_conflict_t *conflict = i->data;
			alpm_pkg_t *rsync, *sync, *sync1, *sync2;

			/* have we already removed one of the conflicting targets? */
			sync1 = _alpm_pkg_find(trans->add, conflict->package1);
			sync2 = _alpm_pkg_find(trans->add, conflict->package2);
			if(!sync1 || !sync2) {
				continue;
			}

			_alpm_log(handle, ALPM_LOG_DEBUG, "conflicting packages in the sync list: '%s' <-> '%s'\n",
					conflict->package1, conflict->package2);

			/* if sync1 provides sync2, we remove sync2 from the targets, and vice versa */
			alpm_depend_t *dep1 = _alpm_splitdep(conflict->package1);
			alpm_depend_t *dep2 = _alpm_splitdep(conflict->package2);
			if(_alpm_depcmp(sync1, dep2)) {
				rsync = sync2;
				sync = sync1;
			} else if(_alpm_depcmp(sync2, dep1)) {
				rsync = sync1;
				sync = sync2;
			} else {
				_alpm_log(handle, ALPM_LOG_ERROR, _("unresolvable package conflicts detected\n"));
				handle->pm_errno = ALPM_ERR_CONFLICTING_DEPS;
				ret = -1;
				if(data) {
					alpm_conflict_t *newconflict = _alpm_conflict_dup(conflict);
					if(newconflict) {
						*data = alpm_list_add(*data, newconflict);
					}
				}
				alpm_list_free_inner(deps, (alpm_list_fn_free)_alpm_conflict_free);
				alpm_list_free(deps);
				_alpm_dep_free(dep1);
				_alpm_dep_free(dep2);
				goto cleanup;
			}
			_alpm_dep_free(dep1);
			_alpm_dep_free(dep2);

			/* Prints warning */
			_alpm_log(handle, ALPM_LOG_WARNING,
					_("removing '%s' from target list because it conflicts with '%s'\n"),
					rsync->name, sync->name);
			trans->add = alpm_list_remove(trans->add, rsync, _alpm_pkg_cmp, NULL);
			/* rsync is not a transaction target anymore */
			trans->unresolvable = alpm_list_add(trans->unresolvable, rsync);
			continue;
		}

		alpm_list_free_inner(deps, (alpm_list_fn_free)_alpm_conflict_free);
		alpm_list_free(deps);
		deps = NULL;

		/* 2. we check for target vs db conflicts (and resolve)*/
		_alpm_log(handle, ALPM_LOG_DEBUG, "check targets vs db and db vs targets\n");
		deps = _alpm_outerconflicts(handle->db_local, trans->add);

		for(i = deps; i; i = i->next) {
			alpm_conflict_t *conflict = i->data;

			/* if conflict->package2 (the local package) is not elected for removal,
			   we ask the user */
			int found = 0;
			for(j = trans->add; j && !found; j = j->next) {
				alpm_pkg_t *spkg = j->data;
				if(_alpm_pkg_find(spkg->removes, conflict->package2)) {
					found = 1;
				}
			}
			if(found) {
				continue;
			}

			_alpm_log(handle, ALPM_LOG_DEBUG, "package '%s' conflicts with '%s'\n",
					conflict->package1, conflict->package2);

			alpm_pkg_t *sync = _alpm_pkg_find(trans->add, conflict->package1);
			alpm_pkg_t *local = _alpm_db_get_pkgfromcache(handle->db_local, conflict->package2);
			int doremove = 0;
			QUESTION(handle, ALPM_QUESTION_CONFLICT_PKG, conflict->package1,
							conflict->package2, conflict->reason->name, &doremove);
			if(doremove) {
				/* append to the removes list */
				_alpm_log(handle, ALPM_LOG_DEBUG, "electing '%s' for removal\n", conflict->package2);
				sync->removes = alpm_list_add(sync->removes, local);
			} else { /* abort */
				_alpm_log(handle, ALPM_LOG_ERROR, _("unresolvable package conflicts detected\n"));
				handle->pm_errno = ALPM_ERR_CONFLICTING_DEPS;
				ret = -1;
				if(data) {
					alpm_conflict_t *newconflict = _alpm_conflict_dup(conflict);
					if(newconflict) {
						*data = alpm_list_add(*data, newconflict);
					}
				}
				alpm_list_free_inner(deps, (alpm_list_fn_free)_alpm_conflict_free);
				alpm_list_free(deps);
				goto cleanup;
			}
		}
		EVENT(handle, ALPM_EVENT_INTERCONFLICTS_DONE, NULL, NULL);
		alpm_list_free_inner(deps, (alpm_list_fn_free)_alpm_conflict_free);
		alpm_list_free(deps);
	}

	/* Build trans->remove list */
	for(i = trans->add; i; i = i->next) {
		alpm_pkg_t *spkg = i->data;
		for(j = spkg->removes; j; j = j->next) {
			alpm_pkg_t *rpkg = j->data;
			if(!_alpm_pkg_find(trans->remove, rpkg->name)) {
				alpm_pkg_t *copy;
				_alpm_log(handle, ALPM_LOG_DEBUG, "adding '%s' to remove list\n", rpkg->name);
				if(_alpm_pkg_dup(rpkg, &copy) == -1) {
					return -1;
				}
				trans->remove = alpm_list_add(trans->remove, copy);
			}
		}
	}

	if(!(trans->flags & ALPM_TRANS_FLAG_NODEPS)) {
		_alpm_log(handle, ALPM_LOG_DEBUG, "checking dependencies\n");
		deps = alpm_checkdeps(handle, _alpm_db_get_pkgcache(handle->db_local),
				trans->remove, trans->add, 1);
		if(deps) {
			handle->pm_errno = ALPM_ERR_UNSATISFIED_DEPS;
			ret = -1;
			if(data) {
				*data = deps;
			} else {
				alpm_list_free_inner(deps, (alpm_list_fn_free)_alpm_depmiss_free);
				alpm_list_free(deps);
			}
			goto cleanup;
		}
	}
	for(i = trans->add; i; i = i->next) {
		/* update download size field */
		alpm_pkg_t *spkg = i->data;
		if(compute_download_size(spkg) != 0) {
			ret = -1;
			goto cleanup;
		}
	}

cleanup:
	alpm_list_free(remove);

	return ret;
}

/** Returns the size of the files that will be downloaded to install a
 * package.
 * @param newpkg the new package to upgrade to
 * @return the size of the download
 */
off_t SYMEXPORT alpm_pkg_download_size(alpm_pkg_t *newpkg)
{
	if(!(newpkg->infolevel & INFRQ_DSIZE)) {
		compute_download_size(newpkg);
	}
	return newpkg->download_size;
}

static int endswith(const char *filename, const char *extension)
{
	const char *s = filename + strlen(filename) - strlen(extension);
	return strcmp(s, extension) == 0;
}

/** Applies delta files to create an upgraded package file.
 *
 * All intermediate files are deleted, leaving only the starting and
 * ending package files.
 *
 * @param handle the context handle
 *
 * @return 0 if all delta files were able to be applied, 1 otherwise.
 */
static int apply_deltas(alpm_handle_t *handle)
{
	alpm_list_t *i;
	int deltas_found = 0, ret = 0;
	const char *cachedir = _alpm_filecache_setup(handle);
	alpm_trans_t *trans = handle->trans;

	for(i = trans->add; i; i = i->next) {
		alpm_pkg_t *spkg = i->data;
		alpm_list_t *delta_path = spkg->delta_path;
		alpm_list_t *dlts = NULL;

		if(!delta_path) {
			continue;
		}

		if(!deltas_found) {
			/* only show this if we actually have deltas to apply, and it is before
			 * the very first one */
			EVENT(handle, ALPM_EVENT_DELTA_PATCHES_START, NULL, NULL);
			deltas_found = 1;
		}

		for(dlts = delta_path; dlts; dlts = dlts->next) {
			alpm_delta_t *d = dlts->data;
			char *delta, *from, *to;
			char command[PATH_MAX];
			size_t len = 0;

			delta = _alpm_filecache_find(handle, d->delta);
			/* the initial package might be in a different cachedir */
			if(dlts == delta_path) {
				from = _alpm_filecache_find(handle, d->from);
			} else {
				/* len = cachedir len + from len + '/' + null */
				len = strlen(cachedir) + strlen(d->from) + 2;
				MALLOC(from, len, RET_ERR(handle, ALPM_ERR_MEMORY, 1));
				snprintf(from, len, "%s/%s", cachedir, d->from);
			}
			len = strlen(cachedir) + strlen(d->to) + 2;
			MALLOC(to, len, RET_ERR(handle, ALPM_ERR_MEMORY, 1));
			snprintf(to, len, "%s/%s", cachedir, d->to);

			/* build the patch command */
			if(endswith(to, ".gz")) {
				/* special handling for gzip : we disable timestamp with -n option */
				snprintf(command, PATH_MAX, "xdelta3 -d -q -R -c -s %s %s | gzip -n > %s", from, delta, to);
			} else {
				snprintf(command, PATH_MAX, "xdelta3 -d -q -s %s %s %s", from, delta, to);
			}

			_alpm_log(handle, ALPM_LOG_DEBUG, "command: %s\n", command);

			EVENT(handle, ALPM_EVENT_DELTA_PATCH_START, d->to, d->delta);

			int retval = system(command);
			if(retval == 0) {
				EVENT(handle, ALPM_EVENT_DELTA_PATCH_DONE, NULL, NULL);

				/* delete the delta file */
				unlink(delta);

				/* Delete the 'from' package but only if it is an intermediate
				 * package. The starting 'from' package should be kept, just
				 * as if deltas were not used. */
				if(dlts != delta_path) {
					unlink(from);
				}
			}
			FREE(from);
			FREE(to);
			FREE(delta);

			if(retval != 0) {
				/* one delta failed for this package, cancel the remaining ones */
				EVENT(handle, ALPM_EVENT_DELTA_PATCH_FAILED, NULL, NULL);
				handle->pm_errno = ALPM_ERR_DLT_PATCHFAILED;
				ret = 1;
				break;
			}
		}
	}
	if(deltas_found) {
		EVENT(handle, ALPM_EVENT_DELTA_PATCHES_DONE, NULL, NULL);
	}

	return ret;
}

/**
 * Prompts to delete the file now that we know it is invalid.
 * @param handle the context handle
 * @param filename the absolute path of the file to test
 * @param reason an error code indicating the reason for package invalidity
 *
 * @return 1 if file was removed, 0 otherwise
 */
static int prompt_to_delete(alpm_handle_t *handle, const char *filepath,
		enum _alpm_errno_t reason)
{
	int doremove = 0;
	QUESTION(handle, ALPM_QUESTION_CORRUPTED_PKG, (char *)filepath,
			&reason, NULL, &doremove);
	if(doremove) {
		unlink(filepath);
	}
	return doremove;
}

static int validate_deltas(alpm_handle_t *handle, alpm_list_t *deltas)
{
	alpm_list_t *i, *errors = NULL;

	if(!deltas) {
		return 0;
	}

	/* Check integrity of deltas */
	EVENT(handle, ALPM_EVENT_DELTA_INTEGRITY_START, NULL, NULL);
	for(i = deltas; i; i = i->next) {
		alpm_delta_t *d = i->data;
		char *filepath = _alpm_filecache_find(handle, d->delta);

		if(_alpm_test_checksum(filepath, d->delta_md5, ALPM_CSUM_MD5)) {
			errors = alpm_list_add(errors, filepath);
		} else {
			FREE(filepath);
		}
	}
	EVENT(handle, ALPM_EVENT_DELTA_INTEGRITY_DONE, NULL, NULL);

	if(errors) {
		for(i = errors; i; i = i->next) {
			char *filepath = i->data;
			prompt_to_delete(handle, filepath, ALPM_ERR_DLT_INVALID);
			FREE(filepath);
		}
		alpm_list_free(errors);
		handle->pm_errno = ALPM_ERR_DLT_INVALID;
		return -1;
	}
	return 0;
}

static int find_dl_candidates(alpm_db_t *repo, alpm_list_t **files, alpm_list_t **deltas)
{
	alpm_list_t *i;
	alpm_handle_t *handle = repo->handle;

	for(i = handle->trans->add; i; i = i->next) {
		alpm_pkg_t *spkg = i->data;

		if(spkg->origin != PKG_FROM_FILE && repo == spkg->origin_data.db) {
			alpm_list_t *delta_path = spkg->delta_path;

			if(!repo->servers) {
				handle->pm_errno = ALPM_ERR_SERVER_NONE;
				_alpm_log(handle, ALPM_LOG_ERROR, "%s: %s\n",
						alpm_strerror(handle->pm_errno), repo->treename);
				return 1;
			}

			if(delta_path) {
				/* using deltas */
				alpm_list_t *dlts;
				for(dlts = delta_path; dlts; dlts = dlts->next) {
					alpm_delta_t *delta = dlts->data;
					if(delta->download_size != 0) {
						struct dload_payload *dpayload;

						CALLOC(dpayload, 1, sizeof(*dpayload), RET_ERR(handle, ALPM_ERR_MEMORY, -1));
						STRDUP(dpayload->remote_name, delta->delta, RET_ERR(handle, ALPM_ERR_MEMORY, -1));
						dpayload->max_size = delta->download_size;
						dpayload->servers = repo->servers;

						*files = alpm_list_add(*files, dpayload);
					}
					/* keep a list of all the delta files for md5sums */
					*deltas = alpm_list_add(*deltas, delta);
				}

			} else if(spkg->download_size != 0) {
				struct dload_payload *payload;

				ASSERT(spkg->filename != NULL, RET_ERR(handle, ALPM_ERR_PKG_INVALID_NAME, -1));
				CALLOC(payload, 1, sizeof(*payload), RET_ERR(handle, ALPM_ERR_MEMORY, -1));
				STRDUP(payload->remote_name, spkg->filename, RET_ERR(handle, ALPM_ERR_MEMORY, -1));
				payload->max_size = spkg->size;
				payload->servers = repo->servers;

				*files = alpm_list_add(*files, payload);
			}
		}
	}

	return 0;
}

static int download_files(alpm_handle_t *handle, alpm_list_t **deltas)
{
	const char *cachedir;
	alpm_list_t *i, *files = NULL;
	int errors = 0;

	cachedir = _alpm_filecache_setup(handle);
	handle->trans->state = STATE_DOWNLOADING;

	/* Total progress - figure out the total download size if required to
	 * pass to the callback. This function is called once, and it is up to the
	 * frontend to compute incremental progress. */
	if(handle->totaldlcb) {
		off_t total_size = (off_t)0;
		/* sum up the download size for each package and store total */
		for(i = handle->trans->add; i; i = i->next) {
			alpm_pkg_t *spkg = i->data;
			total_size += spkg->download_size;
		}
		handle->totaldlcb(total_size);
	}

	for(i = handle->dbs_sync; i; i = i->next) {
		errors += find_dl_candidates(i->data, &files, deltas);
	}

	if(files) {
		EVENT(handle, ALPM_EVENT_RETRIEVE_START, NULL, NULL);
		for(i = files; i; i = i->next) {
			struct dload_payload *payload = i->data;
			const alpm_list_t *server;
			int ret = -1;

			for(server = payload->servers; server; server = server->next) {
				const char *server_url = server->data;
				size_t len;

				/* print server + filename into a buffer */
				len = strlen(server_url) + strlen(payload->remote_name) + 2;
				MALLOC(payload->fileurl, len, RET_ERR(handle, ALPM_ERR_MEMORY, -1));
				snprintf(payload->fileurl, len, "%s/%s", server_url, payload->remote_name);
				payload->handle = handle;
				payload->allow_resume = 1;

				ret = _alpm_download(payload, cachedir, NULL);
				if(ret != -1) {
					break;
				}
			}
			if(ret == -1) {
				errors++;
				_alpm_log(handle, ALPM_LOG_WARNING, _("failed to retrieve some files\n"));
			}
		}

		alpm_list_free_inner(files, (alpm_list_fn_free)_alpm_dload_payload_reset);
		FREELIST(files);
	}

	for(i = handle->trans->add; i; i = i->next) {
		alpm_pkg_t *pkg = i->data;
		pkg->infolevel &= ~INFRQ_DSIZE;
		pkg->download_size = 0;
	}

	/* clear out value to let callback know we are done */
	if(handle->totaldlcb) {
		handle->totaldlcb(0);
	}

	return errors;
}

static int check_validity(alpm_handle_t *handle,
		size_t total, size_t total_bytes)
{
	struct validity {
		alpm_pkg_t *pkg;
		char *path;
		alpm_siglist_t *siglist;
		alpm_siglevel_t level;
		enum _alpm_errno_t error;
	};
	size_t current = 0, current_bytes = 0;
	alpm_list_t *i, *errors = NULL;

	/* Check integrity of packages */
	EVENT(handle, ALPM_EVENT_INTEGRITY_START, NULL, NULL);

	for(i = handle->trans->add; i; i = i->next, current++) {
		struct validity v = { i->data, NULL, NULL, 0, 0 };
		int percent = (int)(((double)current_bytes / total_bytes) * 100);

		PROGRESS(handle, ALPM_PROGRESS_INTEGRITY_START, "", percent,
				total, current);
		if(v.pkg->origin == PKG_FROM_FILE) {
			continue; /* pkg_load() has been already called, this package is valid */
		}

		current_bytes += v.pkg->size;
		v.path = _alpm_filecache_find(handle, v.pkg->filename);
		v.level = alpm_db_get_siglevel(alpm_pkg_get_db(v.pkg));

		if(_alpm_pkg_validate_internal(handle, v.path, v.pkg,
					v.level, &v.siglist) == -1) {
			v.error = handle->pm_errno;
			struct validity *invalid = malloc(sizeof(struct validity));
			memcpy(invalid, &v, sizeof(struct validity));
			errors = alpm_list_add(errors, invalid);
		} else {
			alpm_siglist_cleanup(v.siglist);
			free(v.siglist);
			free(v.path);
		}
	}

	PROGRESS(handle, ALPM_PROGRESS_INTEGRITY_START, "", 100,
			total, current);
	EVENT(handle, ALPM_EVENT_INTEGRITY_DONE, NULL, NULL);

	if(errors) {
		int tryagain = 0;
		for(i = errors; i; i = i->next) {
			struct validity *v = i->data;
			if(v->error == ALPM_ERR_PKG_INVALID_SIG) {
				int retry = _alpm_process_siglist(handle, v->pkg->name, v->siglist,
						v->level & ALPM_SIG_PACKAGE_OPTIONAL,
						v->level & ALPM_SIG_PACKAGE_MARGINAL_OK,
						v->level & ALPM_SIG_PACKAGE_UNKNOWN_OK);
				tryagain += retry;
			} else if(v->error == ALPM_ERR_PKG_INVALID_CHECKSUM) {
				prompt_to_delete(handle, v->path, v->error);
			}
			alpm_siglist_cleanup(v->siglist);
			free(v->siglist);
			free(v->path);
			free(v);
		}
		alpm_list_free(errors);

		if(tryagain == 0) {
			if(!handle->pm_errno) {
				RET_ERR(handle, ALPM_ERR_PKG_INVALID, -1);
			}
			return -1;
		}
		/* we were told at least once we can try again */
		return 1;
	}

	return 0;
}

static int load_packages(alpm_handle_t *handle, alpm_list_t **data,
		size_t total, size_t total_bytes)
{
	size_t current = 0, current_bytes = 0;
	int errors = 0;
	alpm_list_t *i;

	/* load packages from disk now that they are known-valid */
	EVENT(handle, ALPM_EVENT_LOAD_START, NULL, NULL);

	for(i = handle->trans->add; i; i = i->next, current++) {
		alpm_pkg_t *spkg = i->data;
		char *filepath;
		int percent = (int)(((double)current_bytes / total_bytes) * 100);

		PROGRESS(handle, ALPM_PROGRESS_LOAD_START, "", percent,
				total, current);
		if(spkg->origin == PKG_FROM_FILE) {
			continue; /* pkg_load() has been already called, this package is valid */
		}

		current_bytes += spkg->size;
		filepath = _alpm_filecache_find(handle, spkg->filename);

		/* load the package file and replace pkgcache entry with it in the target list */
		/* TODO: alpm_pkg_get_db() will not work on this target anymore */
		_alpm_log(handle, ALPM_LOG_DEBUG,
				"replacing pkgcache entry with package file for target %s\n",
				spkg->name);
		alpm_pkg_t *pkgfile =_alpm_pkg_load_internal(handle, filepath, 1);
		if(!pkgfile) {
			errors++;
			*data = alpm_list_add(*data, strdup(spkg->filename));
			free(filepath);
			continue;
		}
		free(filepath);
		/* copy over the install reason */
		pkgfile->reason = spkg->reason;
		i->data = pkgfile;
		/* spkg has been removed from the target list, so we can free the
		 * sync-specific fields */
		_alpm_pkg_free_trans(spkg);
	}

	PROGRESS(handle, ALPM_PROGRESS_LOAD_START, "", 100,
			total, current);
	EVENT(handle, ALPM_EVENT_LOAD_DONE, NULL, NULL);

	if(errors) {
		if(!handle->pm_errno) {
			RET_ERR(handle, ALPM_ERR_PKG_INVALID, -1);
		}
		return -1;
	}

	return 0;
}

int _alpm_sync_commit(alpm_handle_t *handle, alpm_list_t **data)
{
	alpm_list_t *i, *deltas = NULL;
	size_t total = 0, total_bytes = 0;
	alpm_trans_t *trans = handle->trans;

	if(download_files(handle, &deltas)) {
		alpm_list_free(deltas);
		return -1;
	}

	if(validate_deltas(handle, deltas)) {
		alpm_list_free(deltas);
		return -1;
	}
	alpm_list_free(deltas);

	/* Use the deltas to generate the packages */
	if(apply_deltas(handle)) {
		return -1;
	}

	/* get the total size of all packages so we can adjust the progress bar more
	 * realistically if there are small and huge packages involved */
	for(i = trans->add; i; i = i->next) {
		alpm_pkg_t *spkg = i->data;
		if(spkg->origin != PKG_FROM_FILE) {
			total_bytes += spkg->size;
		}
		total++;
	}
	/* this can only happen maliciously */
	total_bytes = total_bytes ? total_bytes : 1;

	/* this one is special: -1 is failure, 1 is retry, 0 is success */
	while(1) {
		int ret = check_validity(handle, total, total_bytes);
		if(ret == 0) {
			break;
		} else if(ret < 0) {
			return -1;
		}
	}

	if(trans->flags & ALPM_TRANS_FLAG_DOWNLOADONLY) {
		return 0;
	}

	if(load_packages(handle, data, total, total_bytes)) {
		return -1;
	}

	trans->state = STATE_COMMITING;

	/* fileconflict check */
	if(!(trans->flags & ALPM_TRANS_FLAG_FORCE)) {
		EVENT(handle, ALPM_EVENT_FILECONFLICTS_START, NULL, NULL);

		_alpm_log(handle, ALPM_LOG_DEBUG, "looking for file conflicts\n");
		alpm_list_t *conflict = _alpm_db_find_fileconflicts(handle,
				trans->add, trans->remove);
		if(conflict) {
			if(data) {
				*data = conflict;
			} else {
				alpm_list_free_inner(conflict, (alpm_list_fn_free)_alpm_fileconflict_free);
				alpm_list_free(conflict);
			}
			RET_ERR(handle, ALPM_ERR_FILE_CONFLICTS, -1);
		}

		EVENT(handle, ALPM_EVENT_FILECONFLICTS_DONE, NULL, NULL);
	}

	/* check available disk space */
	if(handle->checkspace) {
		EVENT(handle, ALPM_EVENT_DISKSPACE_START, NULL, NULL);

		_alpm_log(handle, ALPM_LOG_DEBUG, "checking available disk space\n");
		if(_alpm_check_diskspace(handle) == -1) {
			_alpm_log(handle, ALPM_LOG_ERROR, "%s\n", _("not enough free disk space"));
			return -1;
		}

		EVENT(handle, ALPM_EVENT_DISKSPACE_DONE, NULL, NULL);
	}

	/* remove conflicting and to-be-replaced packages */
	if(trans->remove) {
		_alpm_log(handle, ALPM_LOG_DEBUG, "removing conflicting and to-be-replaced packages\n");
		/* we want the frontend to be aware of commit details */
		if(_alpm_remove_packages(handle, 0) == -1) {
			_alpm_log(handle, ALPM_LOG_ERROR, _("could not commit removal transaction\n"));
			return -1;
		}
	}

	/* install targets */
	_alpm_log(handle, ALPM_LOG_DEBUG, "installing packages\n");
	if(_alpm_upgrade_packages(handle) == -1) {
		_alpm_log(handle, ALPM_LOG_ERROR, _("could not commit transaction\n"));
		return -1;
	}

	return 0;
}

/* vim: set ts=2 sw=2 noet: */