sync.c

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/*
 *  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 <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;
    int ret = 0;

    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;
        }

        /* tell the caller that we have a partial */
        ret = 1;
    } 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 ret;
}

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;
    size_t from_sync = 0;
    int ret = 0;
    alpm_trans_t *trans = handle->trans;

    if(data) {
        *data = NULL;
    }

    for(i = trans->add; i; i = i->next) {
        alpm_pkg_t *spkg = i->data;
        from_sync += (spkg->origin == PKG_FROM_SYNCDB);
    }

    /* ensure all sync database are valid if 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);
        }
        /* missing databases are not allowed if we have sync targets */
        if(from_sync && 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;
        alpm_list_t *remove = NULL;
        alpm_list_t *localpkgs;

        /* 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) */
        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);
        alpm_list_free(remove);

        /* 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;
            alpm_errno_t saved_err = handle->pm_errno;
            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;
                if(data) {
                    alpm_list_free_inner(*data, (alpm_list_fn_free)_alpm_depmiss_free);
                    alpm_list_free(*data);
                    *data = NULL;
                }
            } else {
                /* pm_errno was set by resolvedeps, callback may have overwrote it */
                handle->pm_errno = saved_err;
                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:
    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,
        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 struct dload_payload *build_payload(alpm_handle_t *handle,
        const char *filename, size_t size, alpm_list_t *servers)
{
        struct dload_payload *payload;

        CALLOC(payload, 1, sizeof(*payload), RET_ERR(handle, ALPM_ERR_MEMORY, NULL));
        STRDUP(payload->remote_name, filename, RET_ERR(handle, ALPM_ERR_MEMORY, NULL));
        payload->max_size = size;
        payload->servers = servers;
        return payload;
}

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 *payload = build_payload(
                                handle, delta->delta, delta->download_size, repo->servers);
                        ASSERT(payload, return -1);
                        *files = alpm_list_add(*files, payload);
                    }
                    /* 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));
                payload = build_payload(handle, spkg->filename, spkg->size, repo->servers);
                ASSERT(payload, return -1);
                *files = alpm_list_add(*files, payload);
            }
        }
    }

    return 0;
}

static int download_single_file(alpm_handle_t *handle, struct dload_payload *payload,
        const char *cachedir)
{
    const alpm_list_t *server;

    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;

        if(_alpm_download(payload, cachedir, NULL) != -1) {
            return 0;
        }
    }

    return -1;
}

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) {
        /* check for necessary disk space for download */
        if(handle->checkspace) {
            off_t *file_sizes;
            size_t idx, num_files;
            int ret;

            _alpm_log(handle, ALPM_LOG_DEBUG, "checking available disk space for download\n");

            num_files = alpm_list_count(files);
            CALLOC(file_sizes, num_files, sizeof(off_t), goto finish);

            for(i = files, idx = 0; i; i = i->next, idx++) {
                const struct dload_payload *payload = i->data;
                file_sizes[idx] = payload->max_size;
            }

            ret = _alpm_check_downloadspace(handle, cachedir, num_files, file_sizes);
            free(file_sizes);

            if(ret != 0) {
                errors++;
                goto finish;
            }
        }

        EVENT(handle, ALPM_EVENT_RETRIEVE_START, NULL, NULL);
        for(i = files; i; i = i->next) {
            if(download_single_file(handle, i->data, cachedir) == -1) {
                errors++;
                _alpm_log(handle, ALPM_LOG_WARNING, _("failed to retrieve some files\n"));
            }
        }
    }

finish:
    if(files) {
        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;
        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|ALPM_TRANS_FLAG_DBONLY))) {
        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 && !(trans->flags & ALPM_TRANS_FLAG_DBONLY)) {
        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: */