path: root/camel/camel-folder-thread.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 *  Copyright (C) 2000 Ximian Inc.
 *
 *  Authors: Michael Zucchi <notzed@ximian.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * 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, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/* TODO: This could probably be made a camel object, but it isn't really required */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <ctype.h>
#include <glib.h>

#include "camel-folder-thread.h"
#include "e-util/e-memory.h"

#define d(x)

/*#define TIMEIT*/

#ifdef TIMEIT
#include <sys/time.h>
#include <unistd.h>
#endif

static void
container_add_child(CamelFolderThreadNode *node, CamelFolderThreadNode *child)
{
    d(printf("\nAdding child %p to parent %p \n", child, node));
    child->next = node->child;
    node->child = child;
    child->parent = node;
}

static void
container_parent_child(CamelFolderThreadNode *parent, CamelFolderThreadNode *child)
{
    CamelFolderThreadNode *c, *node;

    /* are we already the right parent? */
    if (child->parent == parent)
        return;

    /* would this create a loop? */
    node = parent->parent;
    while (node) {
        if (node == child)
            return;
        node = node->parent;
    }

    /* are we unparented? */
    if (child->parent == NULL) {
        container_add_child(parent, child);
        return;
    }

    /* else remove child from its existing parent, and reparent */
    node = child->parent;
    c = (CamelFolderThreadNode *)&node->child;
    d(printf("scanning children:\n"));
    while (c->next) {
        d(printf(" %p\n", c));
            if (c->next==child) {
            d(printf("found node %p\n", child));
            c->next = c->next->next;
            child->parent = NULL;
            container_add_child(parent, child);
            return;
        }
        c = c->next;
    }

    printf("DAMN, we shouldn't  be here!\n");
}

static void
prune_empty(CamelFolderThread *thread, CamelFolderThreadNode **cp)
{
    CamelFolderThreadNode *child, *next, *c, *lastc;

    /* yes, this is intentional */
    lastc = (CamelFolderThreadNode *)cp;
    while (lastc->next) {
        c = lastc->next;

        d(printf("checking message %p %p (%08x%08x)\n", c,
             c->message, c->message?c->message->message_id.id.part.hi:0,
             c->message?c->message->message_id.id.part.lo:0));
        if (c->message == NULL) {
            if (c->child == NULL) {
                d(printf("removing empty node\n"));
                lastc->next = c->next;
                e_memchunk_free(thread->node_chunks, c);
                continue;
            }
            if (c->parent || c->child->next==0) {
                d(printf("promoting child\n"));
                lastc->next = c->next; /* remove us */
                child = c->child;
                while (child) {
                    next = child->next;

                    child->parent = c->parent;
                    child->next = lastc->next;
                    lastc->next = child;

                    child = next;
                }
                continue;
            }
        }
        prune_empty(thread, &c->child);
        lastc = c;
    }
}

static void
hashloop(void *key, void *value, void *data)
{
    CamelFolderThreadNode *c = value;
    CamelFolderThreadNode *tail = data;

    if (c->parent == NULL) {
        c->next = tail->next;
        tail->next = c;
    }
}

static char *
get_root_subject(CamelFolderThreadNode *c, int *re)
{
    char *s, *p;
    CamelFolderThreadNode *scan;
    
    s = NULL;
    *re = FALSE;
    if (c->message)
        s = (char *)camel_message_info_subject(c->message);
    else {
        /* one of the children will always have a message */
        scan = c->child;
        while (scan) {
            if (scan->message) {
                s = (char *)camel_message_info_subject(scan->message);
                break;
            }
            scan = scan->next;
        }
    }
    if (s != NULL) {
        while (*s) {
            while (isspace(*s))
                s++;
            if (s[0] == 0)
                break;
            if ((s[0] == 'r' || s[0]=='R')
                && (s[1] == 'e' || s[1]=='E')) {
                p = s+2;
                while (isdigit(*p) || (ispunct(*p) && (*p != ':')))
                    p++;
                if (*p==':') {
                    *re = TRUE;
                    s = p+1;
                } else
                    break;
            } else
                break;
        }
        if (*s)
            return s;
    }
    return NULL;
}

/* this can be pretty slow, but not used often */
/* clast cannot be null */
static void
remove_node(CamelFolderThreadNode **list, CamelFolderThreadNode *node, CamelFolderThreadNode **clast)
{
    CamelFolderThreadNode *c;

    /* this is intentional, even if it looks funny */
    /* if we have a parent, then we should remove it from the parent list,
       otherwise we remove it from the root list */
    if (node->parent) {
        c = (CamelFolderThreadNode *)&node->parent->child;
    } else {
        c = (CamelFolderThreadNode *)list;
    }
    while (c->next) {
        if (c->next == node) {
            if (*clast == c->next)
                *clast = c;
            c->next = c->next->next;
            return;
        }
        c = c->next;
    }

    printf("ERROR: removing node %p failed\n", node);
}

static void
group_root_set(CamelFolderThread *thread, CamelFolderThreadNode **cp)
{
    GHashTable *subject_table = g_hash_table_new(g_str_hash, g_str_equal);
    CamelFolderThreadNode *c, *clast, *scan, *container;

    /* gather subject lines */ 
    d(printf("gathering subject lines\n"));
    clast = (CamelFolderThreadNode *)cp;
    c = clast->next;
    while (c) {
        c->root_subject = get_root_subject(c, &c->re);
        if (c->root_subject) {
            container = g_hash_table_lookup(subject_table, c->root_subject);
            if (container == NULL
                || (container->message == NULL && c->message)
                || (container->re == TRUE && !c->re)) {
                g_hash_table_insert(subject_table, c->root_subject, c);
            }
        }
        c = c->next;
    }

    /* merge common subjects? */
    clast = (CamelFolderThreadNode *)cp;
    while (clast->next) {
        c = clast->next;
        d(printf("checking %p %s\n", c, c->root_subject));
        if (c->root_subject
            && (container = g_hash_table_lookup(subject_table, c->root_subject))
            && (container != c)) {
            d(printf(" matching %p %s\n", container, container->root_subject));
            if (c->message == NULL && container->message == NULL) {
                d(printf("merge containers children\n"));
                /* steal the children from c onto container, and unlink c */
                scan = (CamelFolderThreadNode *)&container->child;
                while (scan->next)
                    scan = scan->next;
                scan->next = c->child;
                clast->next = c->next;
                e_memchunk_free(thread->node_chunks, c);
                continue;
            } if (c->message == NULL && container->message != NULL) {
                d(printf("container is non-empty parent\n"));
                remove_node(cp, container, &clast);
                container_add_child(c, container);
            } else if (c->message != NULL && container->message == NULL) {
                d(printf("container is empty child\n"));
                clast->next = c->next;
                container_add_child(container, c);
                continue;
            } else if (c->re && !container->re) {
                d(printf("container is re\n"));
                clast->next = c->next;
                container_add_child(container, c);
                continue;
            } else if (!c->re && container->re) {
                d(printf("container is not re\n"));
                remove_node(cp, container, &clast);
                container_add_child(c, container);
            } else if (c->re && container->re) {
                d(printf("subjects are common %p and %p\n", c, container));

                /* build a phantom node */
                remove_node(cp, container, &clast);
                remove_node(cp, c, &clast);

                scan = e_memchunk_alloc0(thread->node_chunks);

                scan->root_subject = c->root_subject;
                scan->re = c->re && container->re;
                scan->next = c->next;
                clast->next = scan;
                container_add_child(scan, c);
                container_add_child(scan, container);
                clast = scan;
                g_hash_table_insert(subject_table, scan->root_subject, scan);
                continue;
            }
        }
        clast = c;
    }
    g_hash_table_destroy(subject_table);
}

struct _tree_info {
    GHashTable *visited;
};

static int
dump_tree_rec(struct _tree_info *info, CamelFolderThreadNode *c, int depth)
{
    char *p;
    int count=0;

    p = alloca(depth*2+1);
    memset(p, ' ', depth*2);
    p[depth*2] = 0;

    while (c) {
        if (g_hash_table_lookup(info->visited, c)) {
            printf("WARNING: NODE REVISITED: %p\n", c);
        } else {
            g_hash_table_insert(info->visited, c, c);
        }
        if (c->message) {
            printf("%s %p Subject: %s <%.8s>\n", p, c, camel_message_info_subject(c->message), c->message->message_id.id.hash);
            count += 1;
        } else {
            printf("%s %p <empty>\n", p, c);
        }
        if (c->child)
            count += dump_tree_rec(info, c->child, depth+1);
        c = c->next;
    }
    return count;
}

int
camel_folder_threaded_messages_dump(CamelFolderThreadNode *c)
{
    int count;
    struct _tree_info info;

    info.visited = g_hash_table_new(g_direct_hash, g_direct_equal);
    count = dump_tree_rec(&info, c, 0);
    g_hash_table_destroy(info.visited);
    return count;
}

static int
sort_node(const void *a, const void *b)
{
    const CamelFolderThreadNode *a1 = ((CamelFolderThreadNode **)a)[0];
    const CamelFolderThreadNode *b1 = ((CamelFolderThreadNode **)b)[0];

    /* if we have no message, it must be a dummy node, which 
       also means it must have a child, just use that as the
       sort data (close enough?) */
    if (a1->message == NULL)
        a1 = a1->child;
    if (b1->message == NULL)
        b1 = b1->child;
    if (a1->order == b1->order)
        return 0;
    if (a1->order < b1->order)
        return -1;
    else
        return 1;
}

static void
sort_thread(CamelFolderThreadNode **cp)
{
    CamelFolderThreadNode *c, *head, **carray;
    int size=0;

    c = *cp;
    while (c) {
        /* sort the children while we're at it */
        if (c->child)
            sort_thread(&c->child);
        size++;
        c = c->next;
    }
    if (size<2)
        return;
    carray = alloca(size*sizeof(CamelFolderThreadNode *));
    c = *cp;
    size=0;
    while (c) {
        carray[size] = c;
        c = c->next;
        size++;
    }
    qsort(carray, size, sizeof(CamelFolderThreadNode *), sort_node);
    size--;
    head = carray[size];
    head->next = NULL;
    size--;
    do {
        c = carray[size];
        c->next = head;
        head = c;
        size--;
    } while (size>=0);
    *cp = head;
}

static guint id_hash(void *key)
{
    CamelSummaryMessageID *id = (CamelSummaryMessageID *)key;

    return id->id.part.lo;
}

static gint id_equal(void *a, void *b)
{
    return ((CamelSummaryMessageID *)a)->id.id == ((CamelSummaryMessageID *)b)->id.id;
}

/* perform actual threading */
static void
thread_summary(CamelFolderThread *thread, GPtrArray *summary)
{
    GHashTable *id_table, *no_id_table;
    int i;
    CamelFolderThreadNode *c, *child, *head;
#ifdef TIMEIT
    struct timeval start, end;
    unsigned long diff;

    gettimeofday(&start, NULL);
#endif

    id_table = g_hash_table_new((GHashFunc)id_hash, (GCompareFunc)id_equal);
    no_id_table = g_hash_table_new(NULL, NULL);
    for (i=0;i<summary->len;i++) {
        CamelMessageInfo *mi = summary->pdata[i];

        if (mi->message_id.id.id) {
            c = g_hash_table_lookup(id_table, &mi->message_id);
            /* check for duplicate messages */
            if (c && c->order) {
                /* if duplicate, just make out it is a no-id message,  but try and insert it
                   into the right spot in the tree */
                d(printf("doing: (duplicate message id)\n"));
                c = e_memchunk_alloc0(thread->node_chunks);
                g_hash_table_insert(no_id_table, (void *)mi, c);
            } else if (!c) {
                d(printf("doing : %08x%08x (%s)\n", mi->message_id.id.part.hi, mi->message_id.id.part.lo, camel_message_info_subject(mi)));
                c = e_memchunk_alloc0(thread->node_chunks);
                g_hash_table_insert(id_table, (void *)&mi->message_id, c);
            }
        } else {
            d(printf("doing : (no message id)\n"));
            c = e_memchunk_alloc0(thread->node_chunks);
            g_hash_table_insert(no_id_table, (void *)mi, c);
        }

        c->message = mi;
        c->order = i+1;
        child = c;
        if (mi->references) {
            int j;

            d(printf("references:\n"));
            for (j=0;j<mi->references->size;j++) {
                /* should never be empty, but just incase */
                if (mi->references->references[j].id.id == 0)
                    continue;

                c = g_hash_table_lookup(id_table, &mi->references->references[j]);
                if (c == NULL) {
                    d(printf("not found\n"));
                    c = e_memchunk_alloc0(thread->node_chunks);
                    g_hash_table_insert(id_table, &mi->references->references[j], c);
                }
                if (c!=child)
                    container_parent_child(c, child);
                child = c;
            }
        }
    }

    d(printf("\n\n"));
    /* build a list of root messages (no parent) */
    head = NULL;
    g_hash_table_foreach(id_table, hashloop, &head);
    g_hash_table_foreach(no_id_table, hashloop, &head);

    g_hash_table_destroy(id_table);
    g_hash_table_destroy(no_id_table);

    /* remove empty parent nodes */
    prune_empty(thread, &head);
    
    /* find any siblings which missed out - but only if we are allowing threading by subject */
    if (thread->subject)
        group_root_set (thread, &head);

#if 0
    printf("finished\n");
    i = camel_folder_thread_messages_dump(head);
    printf("%d count, %d items in tree\n", uids->len, i);
#endif

    sort_thread(&head);

    /* remove any phantom nodes, this could possibly be put in group_root_set()? */
    c = (CamelFolderThreadNode *)&head;
    while (c && c->next) {
        CamelFolderThreadNode *scan, *newtop;

        child = c->next;
        if (child->message == NULL) {
            newtop = child->child;
            /* unlink pseudo node */
            c->next = newtop;

            /* link its siblings onto the end of its children */
            scan = (CamelFolderThreadNode *)&newtop->child;
            while (scan->next)
                scan = scan->next;
            scan->next = newtop->next;
            /* and link the now 'real' node into the list */
            newtop->next = child->next;
            c = newtop;
            e_memchunk_free(thread->node_chunks, child);
        } else {
            c = child;
        }
    }

    /* this is only debug assertion stuff */
    c = (CamelFolderThreadNode *)&head;
    while (c->next) {
        c = c->next;
        if (c->message == NULL)
            g_warning("threading missed removing a pseudo node: %s\n", c->root_subject);
    }

    thread->tree = head;

#ifdef TIMEIT
    gettimeofday(&end, NULL);
    diff = end.tv_sec * 1000 + end.tv_usec/1000;
    diff -= start.tv_sec * 1000 + start.tv_usec/1000;
    printf("Message threading %d messages took %ld.%03ld seconds\n",
           summary->len, diff / 1000, diff % 1000);
#endif
}

/**
 * camel_folder_thread_messages_new:
 * @folder: 
 * @uids: The subset of uid's to thread.  If NULL. then thread all
 * uid's in @folder.
 * @thread_subject: thread based on subject also
 * 
 * Thread a (subset) of the messages in a folder.  And sort the result
 * in summary order.
 *
 * If @thread_subject is %TRUE, messages with
 * related subjects will also be threaded. The default behaviour is to
 * only thread based on message-id.
 * 
 * This function is probably to be removed soon.
 *
 * Return value: A CamelFolderThread contianing a tree of CamelFolderThreadNode's
 * which represent the threaded structure of the messages.
 **/
CamelFolderThread *
camel_folder_thread_messages_new (CamelFolder *folder, GPtrArray *uids, gboolean thread_subject)
{
    CamelFolderThread *thread;
    GHashTable *wanted = NULL;
    GPtrArray *summary;
    GPtrArray *fsummary;
    int i;

    thread = g_malloc(sizeof(*thread));
    thread->refcount = 1;
    thread->subject = thread_subject;
    thread->tree = NULL;
    thread->node_chunks = e_memchunk_new(32, sizeof(CamelFolderThreadNode));
    thread->folder = folder;
    camel_object_ref((CamelObject *)folder);

    /* get all of the summary items of interest in summary order */
    if (uids) {
        wanted = g_hash_table_new(g_str_hash, g_str_equal);
        for (i=0;i<uids->len;i++)
            g_hash_table_insert(wanted, uids->pdata[i], uids->pdata[i]);
    }

    fsummary = camel_folder_get_summary(folder);
    thread->summary = summary = g_ptr_array_new();

    for (i=0;i<fsummary->len;i++) {
        CamelMessageInfo *info = fsummary->pdata[i];

        if (wanted == NULL || g_hash_table_lookup(wanted, camel_message_info_uid(info)) != NULL) {
            camel_folder_ref_message_info(folder, info);
            g_ptr_array_add(summary, info);
        }
    }

    camel_folder_free_summary(folder, fsummary);

    thread_summary(thread, summary);

    g_hash_table_destroy(wanted);

    return thread;
}

/* add any still there, in the existing order */
static void
add_present_rec(CamelFolderThread *thread, GHashTable *have, GPtrArray *summary, CamelFolderThreadNode *node)
{
    while (node) {
        const char *uid = camel_message_info_uid(node->message);

        if (g_hash_table_lookup(have, (char *)uid)) {
            g_hash_table_remove(have, (char *)camel_message_info_uid(node->message));
            g_ptr_array_add(summary, (void *) node->message);
        } else {
            camel_folder_free_message_info(thread->folder, (CamelMessageInfo *)node->message);
        }

        if (node->child)
            add_present_rec(thread, have, summary, node->child);
        node = node->next;
    }
}

void
camel_folder_thread_messages_apply(CamelFolderThread *thread, GPtrArray *uids)
{
    int i;
    GPtrArray *all;
    GHashTable *table;
    CamelMessageInfo *info;

    all = g_ptr_array_new();
    table = g_hash_table_new(g_str_hash, g_str_equal);
    for (i=0;i<uids->len;i++)
        g_hash_table_insert(table, uids->pdata[i], uids->pdata[i]);

    add_present_rec(thread, table, all, thread->tree);

    /* add any new ones, in supplied order */
    for (i=0;i<uids->len;i++)
        if (g_hash_table_lookup(table, uids->pdata[i]) && (info = camel_folder_get_message_info(thread->folder, uids->pdata[i])))
            g_ptr_array_add(all, info);

    g_hash_table_destroy(table);
    thread_summary(thread, all);

    g_ptr_array_free(thread->summary, TRUE);
    thread->summary = all;
}

void
camel_folder_thread_messages_ref(CamelFolderThread *thread)
{
    thread->refcount++;
}

/**
 * camel_folder_thread_messages_unref:
 * @thread: 
 * 
 * Free all memory associated with the thread descriptor @thread.
 **/
void
camel_folder_thread_messages_unref(CamelFolderThread *thread)
{
    if (thread->refcount > 1) {
        thread->refcount--;
        return;
    }

    if (thread->folder) {
        int i;

        for (i=0;i<thread->summary->len;i++)
            camel_folder_free_message_info(thread->folder, thread->summary->pdata[i]);
        g_ptr_array_free(thread->summary, TRUE);
        camel_object_unref((CamelObject *)thread->folder);
    }
    e_memchunk_destroy(thread->node_chunks);
    g_free(thread);
}

#if 0
/**
 * camel_folder_thread_messages_new_summary:
 * @summary: Array of CamelMessageInfo's to thread.
 * 
 * Thread a list of MessageInfo's.  The summary must remain valid for the
 * life of the CamelFolderThread created by this function, and it is upto the
 * caller to ensure this.
 * 
 * Return value: A CamelFolderThread contianing a tree of CamelFolderThreadNode's
 * which represent the threaded structure of the messages.
 **/
CamelFolderThread *
camel_folder_thread_messages_new_summary(GPtrArray *summary)
{
    CamelFolderThread *thread;

#ifdef TIMEIT
    struct timeval start, end;
    unsigned long diff;

    gettimeofday(&start, NULL);
#endif

    thread = g_malloc(sizeof(*thread));
    thread->refcount = 1;
    thread->tree = NULL;
    thread->node_chunks = e_memchunk_new(32, sizeof(CamelFolderThreadNode));
    thread->folder = NULL;
    thread->summary = NULL;

    thread_summary(thread, summary);

    return thread;
}

/* scan the list in depth-first fashion */
static void
build_summary_rec(GHashTable *have, GPtrArray *summary, CamelFolderThreadNode *node)
{
    while (node) {
        if (node->message)
            g_hash_table_insert(have, (char *)camel_message_info_uid(node->message), node->message);
        g_ptr_array_add(summary, node);
        if (node->child)
            build_summary_rec(have, summary, node->child);
        node = node->next;
    }
}

void
camel_folder_thread_messages_add(CamelFolderThread *thread, GPtrArray *summary)
{
    GPtrArray *all;
    int i;
    GHashTable *table;

    /* Instead of working out all the complex in's and out's of
       trying to do an incremental summary generation, just redo the whole
       thing with the summary in the current order - so it comes out
       in the same order */

    all = g_ptr_array_new();
    table = g_hash_table_new(g_str_hash, g_str_equal);
    build_summary_rec(table, all, thread->tree);
    for (i=0;i<summary->len;i++) {
        CamelMessageInfo *info = summary->pdata[i];

        /* check its not already there, we dont want duplicates */
        if (g_hash_table_lookup(table, camel_message_info_uid(info)) == NULL)
            g_ptr_array_add(all, info);
    }
    g_hash_table_destroy(table);

    /* reset the tree, and rebuild fully */
    thread->tree = NULL;
    e_memchunk_empty(thread->node_chunks);
    thread_summary(thread, all, NULL);
}

static void
remove_uid_node_rec(CamelFolderThread *thread, GHashTable *table, CamelFolderThreadNode **list, CamelFolderThreadNode *parent)
{
    CamelFolderThreadNode *prev = NULL;
    CamelFolderThreadNode *node, *next, *child, *rest;

    node = (CamelFolderThreadNode *)list;
    next = node->next;
    while (next) {

        if (next->child)
            remove_uid_node_rec(thread, table, &next->child, next);

        /* do we have a node to remove? */
        if (next->message && g_hash_table_lookup(table, (char *)camel_message_info_uid(node->message))) {
            child = next->child;
            if (child) {
                /*
                  node
                  next
                   child
                   lchild
                  rest

                  becomes:
                  node
                  child
                  lchild
                  rest
                */

                rest = next->next;
                node->next = child;
                e_memchunk_free(thread->node_chunks, next);
                next = child;
                do {
                    lchild = child;
                    child->parent = parent;
                    child = child->next;
                } while (child);
                lchild->next = rest;
            } else {
                /*
                  node
                  next
                  rest
                  becomes:
                  node
                  rest */
                node->next = next->next;
                e_memchunk_free(thread->node_chunks, next);
                next = node->next;
            }
        } else {
            node = next;
            next = node->next;
        }
    }
}

void
camel_folder_thread_messages_remove(CamelFolderThread *thread, GPtrArray *uids)
{
    GHashTable *table;
    int i;

    table = g_hash_table_new(g_str_hash, g_str_equal);
    for (i=0;i<uids->len;i++)
        g_hash_table_insert(table, uids->pdata[i], uids->pdata[i]);

    remove_uid_node_rec(thread, table, &thread->tree, NULL);
    g_hash_table_destroy(table);
}

#endif