+/*
+ * Copyright (C) 2004 Thomas Glanzmann <sithglan@stud.uni-erlangen.de>
+ * Copyright (C) 2004 Tobias Werth <sitowert@stud.uni-erlangen.de>
+ * Copyright (C) 2004 Brian Fundakowski Feldman <green@FreeBSD.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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif /* HAVE_CONFIG_H */
+
+#if HAVE_GDBM
+#include <gdbm.h>
+#elif HAVE_DB4
+#include <db.h>
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#include "mutt.h"
+#ifdef USE_IMAP
+#include "message.h"
+#endif
+#include "mime.h"
+#include "mx.h"
+#include "lib.h"
+#include "md5.h"
+
+#if HAVE_GDBM
+static struct
+header_cache
+{
+ GDBM_FILE db;
+ char *folder;
+ unsigned int crc;
+} HEADER_CACHE;
+#elif HAVE_DB4
+static struct
+header_cache
+{
+ DB_ENV *env;
+ DB *db;
+ unsigned int crc;
+ int fd;
+ char lockfile[_POSIX_PATH_MAX];
+} HEADER_CACHE;
+#endif
+
+typedef union
+{
+ struct timeval timeval;
+ unsigned long long uid_validity;
+} validate;
+
+static void *
+lazy_malloc(size_t siz)
+{
+ if (0 < siz && siz < 4096) {
+ siz = 4096;
+ }
+
+ return safe_malloc(siz);
+}
+
+static void
+lazy_realloc(void *ptr, size_t siz)
+{
+ void **p = (void **)ptr;
+
+ if ( p != NULL
+ && 0 < siz
+ && siz < 4096) {
+ return;
+ }
+
+ safe_realloc(ptr, siz);
+}
+
+static unsigned char *
+dump_int(unsigned int i, unsigned char *d, int *off)
+{
+ lazy_realloc(&d, *off + sizeof(int));
+ memcpy(d + *off, &i, sizeof(int));
+ (*off) += sizeof(int);
+
+ return d;
+}
+
+static void
+restore_int(unsigned int *i, const unsigned char *d, int *off)
+{
+ memcpy(i, d + *off, sizeof(int));
+ (*off) += sizeof(int);
+}
+
+static unsigned char *
+dump_char(char *c, unsigned char *d, int *off)
+{
+ unsigned int size;
+
+ if (c == NULL) {
+ size = 0;
+ d = dump_int(size, d, off);
+ return d;
+ }
+
+ size = mutt_strlen(c) + 1;
+ d = dump_int(size, d, off);
+ lazy_realloc(&d, *off + size);
+ memcpy(d + *off, c, size);
+ *off += size;
+
+ return d;
+}
+
+static unsigned char *
+dump_char_size(char *c, unsigned char *d, int *off, ssize_t size)
+{
+ if (c == NULL) {
+ size = 0;
+ d = dump_int(size, d, off);
+ return d;
+ }
+
+ d = dump_int(size, d, off);
+ lazy_realloc(&d, *off + size);
+ memcpy(d + *off, c, size);
+ *off += size;
+
+ return d;
+}
+
+static void
+restore_char(char **c, const unsigned char *d, int *off)
+{
+ unsigned int size;
+ restore_int(&size, d, off);
+
+ if (size == 0) {
+ *c = NULL;
+ return;
+ }
+
+ *c = safe_malloc(size);
+ memcpy(*c, d + *off, size);
+ *off += size;
+}
+
+static unsigned char *
+dump_address(ADDRESS *a, unsigned char *d, int *off)
+{
+ unsigned int counter = 0;
+ unsigned int start_off = *off;
+
+ d = dump_int(0xdeadbeef, d, off);
+
+ while (a) {
+#ifdef EXACT_ADDRESS
+ d = dump_char(a->val, d, off);
+#endif
+ d = dump_char(a->personal, d, off);
+ d = dump_char(a->mailbox, d, off);
+ d = dump_int(a->group, d, off);
+ a = a->next;
+ counter++;
+ }
+
+ memcpy(d + start_off, &counter, sizeof(int));
+
+ return d;
+}
+
+static void
+restore_address(ADDRESS **a, const unsigned char *d, int *off)
+{
+ unsigned int counter;
+
+ restore_int(&counter, d, off);
+
+ while (counter) {
+ *a = safe_malloc(sizeof(ADDRESS));
+#ifdef EXACT_ADDRESS
+ restore_char(&(*a)->val, d, off);
+#endif
+ restore_char(&(*a)->personal, d, off);
+ restore_char(&(*a)->mailbox, d, off);
+ restore_int((unsigned int *)&(*a)->group, d, off);
+ a = &(*a)->next;
+ counter--;
+ }
+
+ *a = NULL;
+}
+
+static unsigned char *
+dump_list(LIST *l, unsigned char *d, int *off)
+{
+ unsigned int counter = 0;
+ unsigned int start_off = *off;
+
+ d = dump_int(0xdeadbeef, d, off);
+
+ while (l) {
+ d = dump_char(l->data, d, off);
+ l = l->next;
+ counter++;
+ }
+
+ memcpy(d + start_off, &counter, sizeof(int));
+
+ return d;
+}
+
+static void
+restore_list(LIST **l, const unsigned char *d, int *off)
+{
+ unsigned int counter;
+
+ restore_int(&counter, d, off);
+
+ while (counter) {
+ *l = safe_malloc(sizeof(LIST));
+ restore_char(&(*l)->data, d, off);
+ l = &(*l)->next;
+ counter--;
+ }
+
+ *l = NULL;
+}
+
+static unsigned char *
+dump_buffer(BUFFER *b, unsigned char *d, int *off)
+{
+ if (! b) {
+ d = dump_int(0, d, off);
+ return d;
+ } else {
+ d = dump_int(1, d, off);
+ }
+
+ d = dump_char_size(b->data, d, off, b->dsize + 1);
+ d = dump_int(b->dptr - b->data, d, off);
+ d = dump_int(b->dsize, d, off);
+ d = dump_int(b->destroy, d, off);
+
+ return d;
+}
+
+static void
+restore_buffer(BUFFER **b, const unsigned char *d, int *off)
+{
+ unsigned int used;
+ unsigned int offset;
+ restore_int(&used, d, off);
+ if (! used) {
+ return;
+ }
+
+ *b = safe_malloc(sizeof(BUFFER));
+
+ restore_char(& (*b)->data, d, off);
+ restore_int(& offset, d, off);
+ (*b)->dptr = (*b)->data + offset;
+ restore_int(& (*b)->dsize, d, off);
+ restore_int((unsigned int *) & (*b)->destroy, d, off);
+}
+
+static unsigned char *
+dump_parameter(PARAMETER *p, unsigned char *d, int *off)
+{
+ unsigned int counter = 0;
+ unsigned int start_off = *off;
+
+ d = dump_int(0xdeadbeef, d, off);
+
+ while (p) {
+ d = dump_char(p->attribute, d, off);
+ d = dump_char(p->value, d, off);
+ p = p->next;
+ counter++;
+ }
+
+ memcpy(d + start_off, &counter, sizeof(int));
+
+ return d;
+}
+
+static void
+restore_parameter(PARAMETER **p, const unsigned char *d, int *off)
+{
+ unsigned int counter;
+
+ restore_int(&counter, d, off);
+
+ while (counter) {
+ *p = safe_malloc(sizeof(PARAMETER));
+ restore_char(&(*p)->attribute, d, off);
+ restore_char(&(*p)->value, d, off);
+ p = &(*p)->next;
+ counter--;
+ }
+
+ *p = NULL;
+}
+
+static unsigned char *
+dump_body(BODY *c, unsigned char *d, int *off)
+{
+ lazy_realloc(&d, *off + sizeof(BODY));
+ memcpy(d + *off, c, sizeof(BODY));
+ *off += sizeof(BODY);
+
+ d = dump_char(c->xtype, d, off);
+ d = dump_char(c->subtype, d, off);
+
+ d = dump_parameter(c->parameter, d, off);
+
+ d = dump_char(c->description, d, off);
+ d = dump_char(c->form_name, d, off);
+ d = dump_char(c->filename, d, off);
+ d = dump_char(c->d_filename, d, off);
+
+ return d;
+}
+
+static void
+restore_body(BODY *c, const unsigned char *d, int *off)
+{
+ memcpy(c, d + *off, sizeof(BODY));
+ *off += sizeof(BODY);
+
+ restore_char(& c->xtype, d, off);
+ restore_char(& c->subtype, d, off);
+
+ restore_parameter(& c->parameter, d, off);
+
+ restore_char(& c->description, d, off);
+ restore_char(& c->form_name, d, off);
+ restore_char(& c->filename, d, off);
+ restore_char(& c->d_filename, d, off);
+}
+
+static unsigned char *
+dump_envelope(ENVELOPE *e, unsigned char *d, int *off)
+{
+ d = dump_address(e->return_path, d, off);
+ d = dump_address(e->from, d, off);
+ d = dump_address(e->to, d, off);
+ d = dump_address(e->cc, d, off);
+ d = dump_address(e->bcc, d, off);
+ d = dump_address(e->sender, d, off);
+ d = dump_address(e->reply_to, d, off);
+ d = dump_address(e->mail_followup_to, d, off);
+
+ d = dump_char(e->subject, d, off);
+ if (e->real_subj) {
+ d = dump_int(e->real_subj - e->subject, d, off);
+ } else {
+ d = dump_int(-1, d, off);
+ }
+ d = dump_char(e->message_id, d, off);
+ d = dump_char(e->supersedes, d, off);
+ d = dump_char(e->date, d, off);
+ d = dump_char(e->x_label, d, off);
+
+ d = dump_list(e->references, d, off);
+ d = dump_list(e->in_reply_to, d, off);
+ d = dump_list(e->userhdrs, d, off);
+
+ return d;
+}
+
+static void
+restore_envelope(ENVELOPE *e, const unsigned char *d, int *off)
+{
+ int real_subj_off;
+
+ restore_address(& e->return_path, d, off);
+ restore_address(& e->from, d, off);
+ restore_address(& e->to, d, off);
+ restore_address(& e->cc, d, off);
+ restore_address(& e->bcc, d, off);
+ restore_address(& e->sender, d, off);
+ restore_address(& e->reply_to, d, off);
+ restore_address(& e->mail_followup_to, d, off);
+
+ restore_char(& e->subject, d, off);
+ restore_int((unsigned int *) (& real_subj_off), d, off);
+ if (0 <= real_subj_off) {
+ e->real_subj = e->subject + real_subj_off;
+ } else {
+ e->real_subj = NULL;
+ }
+ restore_char(& e->message_id, d, off);
+ restore_char(& e->supersedes, d, off);
+ restore_char(& e->date, d, off);
+ restore_char(& e->x_label, d, off);
+
+ restore_list(& e->references, d, off);
+ restore_list(& e->in_reply_to, d, off);
+ restore_list(& e->userhdrs, d, off);
+}
+
+static
+unsigned int crc32(unsigned int crc, unsigned char const *p, size_t len)
+{
+ int i;
+ while (len--) {
+ crc ^= *p++;
+ for (i = 0; i < 8; i++)
+ crc = (crc >> 1) ^ ((crc & 1) ? 0xedb88320 : 0);
+ }
+ return crc;
+}
+
+static int
+generate_crc32()
+{
+ int crc = 0;
+
+ crc = crc32(crc, (unsigned char const *) "sithglan@stud.uni-erlangen.de[sithglan]|hcache.c|20041108231548|29613", mutt_strlen("sithglan@stud.uni-erlangen.de[sithglan]|hcache.c|20041108231548|29613"));
+
+#if HAVE_LANGINFO_CODESET
+ crc = crc32(crc, (unsigned char const *) Charset, mutt_strlen(Charset));
+ crc = crc32(crc, (unsigned char const *) "HAVE_LANGINFO_CODESET", mutt_strlen("HAVE_LANGINFO_CODESET"));
+#endif
+
+#if EXACT_ADDRESS
+ crc = crc32(crc, (unsigned char const *) "EXACT_ADDRESS", mutt_strlen("EXACT_ADDRESS"));
+#endif
+
+#ifdef USE_POP
+ crc = crc32(crc, (unsigned char const *) "USE_POP", mutt_strlen("USE_POP"));
+#endif
+
+#ifdef MIXMASTER
+ crc = crc32(crc, (unsigned char const *) "MIXMASTER", mutt_strlen("MIXMASTER"));
+#endif
+
+#ifdef USE_IMAP
+ crc = crc32(crc, (unsigned char const *) "USE_IMAP", mutt_strlen("USE_IMAP"));
+#endif
+ return crc;
+}
+
+static int
+crc32_matches(const char *d, unsigned int crc)
+{
+ int off = sizeof(validate);
+ unsigned int mycrc = 0;
+
+ if (! d) {
+ return 0;
+ }
+
+ restore_int(&mycrc, (unsigned char *) d, &off);
+
+ return (crc == mycrc);
+}
+
+/* Append md5sumed folder to path if path is a directory. */
+static const char *
+mutt_hcache_per_folder(const char *path, const char *folder)
+{
+ static char mutt_hcache_per_folder_path[_POSIX_PATH_MAX];
+ struct stat path_stat;
+ MD5_CTX md5;
+ unsigned char md5sum[16];
+ int ret;
+
+ ret = stat(path, &path_stat);
+ if (ret < 0) {
+ return path;
+ }
+
+ if (! S_ISDIR(path_stat.st_mode)) {
+ return path;
+ }
+
+ MD5Init(&md5);
+ MD5Update(&md5, (unsigned char *) folder, strlen(folder));
+ MD5Final(md5sum, &md5);
+
+ ret = snprintf(mutt_hcache_per_folder_path, _POSIX_PATH_MAX,
+ "%s/%02x%02x%02x%02x%02x%02x%02x%02x"
+ "%02x%02x%02x%02x%02x%02x%02x%02x",
+ path, md5sum[0], md5sum[1], md5sum[2], md5sum[3],
+ md5sum[4], md5sum[5], md5sum[6], md5sum[7], md5sum[8],
+ md5sum[9], md5sum[10], md5sum[11], md5sum[12],
+ md5sum[13], md5sum[14], md5sum[15]);
+
+ if (ret <= 0) {
+ return path;
+ }
+
+ return mutt_hcache_per_folder_path;
+}
+
+/* This function transforms a header into a char so that it is useable by
+ * db_store */
+static void *
+mutt_hcache_dump(void *_db, HEADER *h, int *off, unsigned long long uid_validity)
+{
+ struct header_cache *db = _db;
+ unsigned char *d = NULL;
+ *off = 0;
+
+ d = lazy_malloc(sizeof(validate));
+
+ if (uid_validity) {
+ memcpy(d, &uid_validity, sizeof(long long));
+ } else {
+ struct timeval now;
+ gettimeofday(&now, NULL);
+ memcpy(d, &now, sizeof(struct timeval));
+ }
+ *off += sizeof(validate);
+
+ d = dump_int(db->crc, d, off);
+
+ lazy_realloc(&d, *off + sizeof(HEADER));
+ memcpy(d + *off, h, sizeof(HEADER));
+ *off += sizeof(HEADER);
+
+ d = dump_envelope(h->env, d, off);
+ d = dump_body(h->content, d, off);
+ d = dump_char(h->maildir_flags, d, off);
+
+ return d;
+}
+
+HEADER *
+mutt_hcache_restore(const unsigned char *d, HEADER **oh)
+{
+ int off = 0;
+ HEADER *h = mutt_new_header();
+
+ /* skip validate */
+ off += sizeof(validate);
+
+ /* skip crc */
+ off += sizeof(unsigned int);
+
+ memcpy(h, d + off, sizeof(HEADER));
+ off += sizeof(HEADER);
+
+ h->env = mutt_new_envelope();
+ restore_envelope(h->env, d, &off);
+
+ h->content = mutt_new_body();
+ restore_body(h->content, d, &off);
+
+ restore_char(&h->maildir_flags, d, &off);
+
+ /* this is needed for maildir style mailboxes */
+ if (oh) {
+ h->old = (*oh)->old;
+ h->path = safe_strdup((*oh)->path);
+ mutt_free_header (oh);
+ }
+
+ return h;
+}
+
+#if HAVE_GDBM
+
+void *
+mutt_hcache_open(const char *path, const char *folder)
+{
+ struct header_cache *h = safe_calloc(1, sizeof(HEADER_CACHE));
+ int pagesize = atoi(HeaderCachePageSize) ? atoi(HeaderCachePageSize) : 16384;
+ h->db = NULL;
+ h->folder = safe_strdup (folder);
+ h->crc = generate_crc32();
+
+ if (! path || path[0] == '\0') {
+ FREE(& h->folder);
+ FREE(& h);
+ return NULL;
+ }
+
+ path = mutt_hcache_per_folder(path, folder);
+
+ h->db = gdbm_open((char *) path, pagesize, GDBM_WRCREAT, 00600, NULL);
+ if (h->db) {
+ return h;
+ }
+
+ /* if rw failed try ro */
+ h->db = gdbm_open((char *) path, pagesize, GDBM_READER, 00600, NULL);
+ if(h->db) {
+ return h;
+ } else {
+ FREE(& h->folder);
+ FREE(& h);
+
+ return NULL;
+ }
+}
+
+void
+mutt_hcache_close(void *db)
+{
+ struct header_cache *h = db;
+
+ if (! h) {
+ return;
+ }
+
+ gdbm_close(h->db);
+ FREE(& h->folder);
+ FREE(& h);
+}
+
+void *
+mutt_hcache_fetch(void *db, const char *filename, size_t (*keylen)(const char *fn))
+{
+ struct header_cache *h = db;
+ datum key;
+ datum data;
+ char path[_POSIX_PATH_MAX];
+
+ if (! h) {
+ return NULL;
+ }
+
+ strncpy(path, h->folder, sizeof(path));
+ strncat(path, filename, sizeof(path) - mutt_strlen(path));
+
+ key.dptr = path;
+ key.dsize = keylen(path);
+
+ data = gdbm_fetch(h->db, key);
+
+ if (! crc32_matches(data.dptr, h->crc)) {
+ free(data.dptr);
+ return NULL;
+ }
+
+ return data.dptr;
+}
+
+int
+mutt_hcache_store(void *db, const char *filename, HEADER *header, unsigned long long uid_validity, size_t (*keylen)(const char *fn))
+{
+ struct header_cache *h = db;
+ datum key;
+ datum data;
+ char path[_POSIX_PATH_MAX];
+ int ret;
+
+ if (! h) {
+ return -1;
+ }
+
+ strncpy(path, h->folder, sizeof(path));
+ strncat(path, filename, sizeof(path) - mutt_strlen(path));
+
+ key.dptr = path;
+ key.dsize = keylen(path);
+
+ data.dptr = mutt_hcache_dump(db, header, &data.dsize, uid_validity);
+
+ ret = gdbm_store(h->db, key, data, GDBM_REPLACE);
+
+ FREE(& data.dptr);
+
+ return ret;
+}
+
+int
+mutt_hcache_delete(void *db, const char *filename, size_t (*keylen)(const char *fn))
+{
+ datum key;
+ struct header_cache *h = db;
+ char path[_POSIX_PATH_MAX];
+
+ if (! h) {
+ return -1;
+ }
+
+ strncpy(path, h->folder, sizeof(path));
+ strncat(path, filename, sizeof(path) - mutt_strlen(path));
+
+ key.dptr = path;
+ key.dsize = keylen(path);
+
+ return gdbm_delete(h->db, key);
+}
+#elif HAVE_DB4
+
+static void
+mutt_hcache_dbt_init(DBT *dbt, void *data, size_t len)
+{
+ dbt->data = data;
+ dbt->size = dbt->ulen = len;
+ dbt->dlen = dbt->doff = 0;
+ dbt->flags = DB_DBT_USERMEM;
+}
+
+static void
+mutt_hcache_dbt_empty_init(DBT *dbt)
+{
+ dbt->data = NULL;
+ dbt->size = dbt->ulen = dbt->dlen = dbt->doff = 0;
+ dbt->flags = 0;
+}
+
+void *
+mutt_hcache_open(const char *path, const char *folder)
+{
+ struct stat sb;
+ u_int32_t createflags = DB_CREATE;
+ int ret;
+ struct header_cache *h = calloc(1, sizeof(HEADER_CACHE));
+ int pagesize = atoi(HeaderCachePageSize);
+
+
+ h->crc = generate_crc32();
+
+ if (! path || path[0] == '\0') {
+ FREE(& h);
+ return NULL;
+ }
+
+ path = mutt_hcache_per_folder(path, folder);
+
+ snprintf (h->lockfile, _POSIX_PATH_MAX, "%s-lock-hack", path);
+
+ h->fd = open(h->lockfile, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
+ if (h->fd < 0) {
+ FREE (&h);
+ return NULL;
+ }
+
+ if (mx_lock_file(h->lockfile, h->fd, 1, 0, 5)) {
+ close(h->fd);
+ FREE (&h);
+ return NULL;
+ }
+
+ ret = db_env_create(&h->env, 0);
+ if (ret) {
+ mx_unlock_file(h->lockfile, h->fd, 0);
+ close(h->fd);
+ FREE(& h);
+ return NULL;
+ }
+
+ ret = h->env->open(h->env, NULL, DB_INIT_MPOOL | DB_CREATE | DB_PRIVATE, 0600);
+ if (! ret) {
+ ret = db_create(&h->db, h->env, 0);
+ if (ret) {
+ h->env->close(h->env, 0);
+ mx_unlock_file(h->lockfile, h->fd, 0);
+ close(h->fd);
+ FREE(& h);
+ return NULL;
+ }
+ }
+
+ if (stat(path, &sb) != 0 && errno == ENOENT) {
+ createflags |= DB_EXCL;
+ h->db->set_pagesize(h->db, pagesize);
+ }
+
+ ret = h->db->open(h->db, NULL, path, folder, DB_BTREE, createflags, 0600);
+ if (ret) {
+ h->db->close(h->db, 0);
+ h->env->close(h->env, 0);
+ mx_unlock_file(h->lockfile, h->fd, 0);
+ close(h->fd);
+ FREE(& h);
+ return NULL;
+ }
+
+ return h;
+}
+
+void
+mutt_hcache_close(void *db)
+{
+ struct header_cache *h = db;
+ int ret;
+
+ if (! h) {
+ return;
+ }
+
+ h->db->close(h->db, 0);
+ h->env->close(h->env, 0);
+ mx_unlock_file(h->lockfile, h->fd, 0);
+ close(h->fd);
+ FREE(& h);
+}
+
+void *
+mutt_hcache_fetch(void *db, const char *filename, size_t (*keylen)(const char *fn))
+{
+ DBT key;
+ DBT data;
+ struct header_cache *h = db;
+
+ if (! h) {
+ return NULL;
+ }
+
+ filename++; /* skip '/' */
+
+ mutt_hcache_dbt_init(&key, (void *) filename, keylen(filename));
+ mutt_hcache_dbt_empty_init(&data);
+ data.flags = DB_DBT_MALLOC;
+
+ h->db->get(h->db, NULL, &key, &data, 0);
+
+ if (! crc32_matches(data.data, h->crc)) {
+ free(data.data);
+ return NULL;
+ }
+
+ return data.data;
+}
+
+int
+mutt_hcache_store(void *db, const char *filename, HEADER *header, unsigned long long uid_validity, size_t (*keylen)(const char *fn))
+{
+ DBT key;
+ DBT data;
+ int ret;
+ struct header_cache *h = db;
+
+ if (! h) {
+ return -1;
+ }
+
+ filename++; /* skip '/' */
+
+ mutt_hcache_dbt_init(&key, (void *) filename, keylen(filename));
+
+ mutt_hcache_dbt_empty_init(&data);
+ data.flags = DB_DBT_USERMEM;
+ data.data = mutt_hcache_dump(db, header, (signed int *) &data.size, uid_validity);
+ data.ulen = data.size;
+
+ ret = h->db->put(h->db, NULL, &key, &data, 0);
+
+ FREE(& data.data);
+
+ return ret;
+}
+
+int
+mutt_hcache_delete(void *db, const char *filename, size_t (*keylen)(const char *fn))
+{
+ DBT key;
+ struct header_cache *h = db;
+
+ if (! h) {
+ return -1;
+ }
+
+ filename++; /* skip '/' */
+
+ mutt_hcache_dbt_init(&key, (void *) filename, keylen(filename));
+ return h->db->del(h->db, NULL, &key, 0);
+}
+#endif