Merge commit 'meins/master'
[paraslash.git] / aft.c
diff --git a/aft.c b/aft.c
index 23c6c0d..f6cfddf 100644 (file)
--- a/aft.c
+++ b/aft.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2007 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2007-2008 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -12,6 +12,8 @@
 #include "string.h"
 #include <sys/mman.h>
 #include <fnmatch.h>
+#include <sys/shm.h>
+
 #include "afh.h"
 #include "afs.h"
 #include "net.h"
@@ -58,7 +60,9 @@ enum ls_listing_mode {
        /** -lv */
        LS_MODE_VERBOSE,
        /** -lm */
-       LS_MODE_MBOX
+       LS_MODE_MBOX,
+       /** -lc */
+       LS_MODE_CHUNKS
 };
 
 /** The flags accepted by the ls command. */
@@ -660,6 +664,7 @@ int open_and_update_audio_file(struct osl_row *aft_row, long score,
                AFTCOL_CHUNKS, &chunk_table_obj);
        if (ret < 0)
                return ret;
+       afd->afhi.chunk_table = NULL;
        ret = mmap_full_file(path, O_RDONLY, &map.data,
                &map.size, &afd->fd);
        if (ret < 0)
@@ -685,7 +690,7 @@ int open_and_update_audio_file(struct osl_row *aft_row, long score,
                        .score = score,
                        .hash = file_hash
                };
-               struct para_buffer pb = {.buf = NULL};
+               struct para_buffer pb = {.max_size = VERBOSE_LS_OUTPUT_SIZE - 1};
                ret = make_status_items(&d, &pb);
                if (ret < 0)
                        goto err;
@@ -697,10 +702,8 @@ int open_and_update_audio_file(struct osl_row *aft_row, long score,
        aced.old_afsi = &old_afsi;
        afs_event(AFSI_CHANGE, NULL, &aced);
        ret = save_afd(afd);
-       free(afd->afhi.chunk_table);
-       if (ret < 0)
-               goto err;
 err:
+       free(afd->afhi.chunk_table);
        osl_close_disk_object(&chunk_table_obj);
        return ret;
 }
@@ -804,8 +807,8 @@ static char *make_image_lines(struct afs_info *afsi)
 
 static char *make_filename_lines(const char *path, unsigned flags)
 {
-       char *basename, *dirname;
-       char *ret;
+       char *dirname, *ret;
+       const char *basename;
 
        if (!(flags & LS_FLAG_FULL_PATH))
                return make_message("%s: %s\n",
@@ -814,13 +817,46 @@ static char *make_filename_lines(const char *path, unsigned flags)
        dirname = para_dirname(path);
        ret = make_message("%s: %s\n%s: %s\n%s: %s\n",
                status_item_list[SI_PATH], path,
-               status_item_list[SI_DIRECTORY], dirname,
-               status_item_list[SI_BASENAME], basename);
-       free(basename);
+               status_item_list[SI_DIRECTORY], dirname? dirname : "?",
+               status_item_list[SI_BASENAME], basename? basename : "?");
        free(dirname);
        return ret;
 }
 
+static int print_chunk_table(struct ls_data *d, struct para_buffer *b)
+{
+       struct osl_object chunk_table_obj;
+       struct osl_row *aft_row;
+       int ret, i;
+       char *buf;
+
+       ret = aft_get_row_of_hash(d->hash, &aft_row);
+       if (ret < 0)
+               return ret;
+       ret = osl_open_disk_object(audio_file_table, aft_row,
+               AFTCOL_CHUNKS, &chunk_table_obj);
+       if (ret < 0)
+               return ret;
+       ret = para_printf(b, "%s\n"
+               "chunk_time: %lu:%lu\nchunk_offsets: ",
+               d->path,
+               (long unsigned) d->afhi.chunk_tv.tv_sec,
+               (long unsigned) d->afhi.chunk_tv.tv_usec
+       );
+       if (ret < 0)
+               goto out;
+       buf = chunk_table_obj.data;
+       for (i = 0; i <= d->afhi.chunks_total; i++) {
+               ret = para_printf(b, "%u ", (unsigned) read_u32(buf + 4 * i));
+               if (ret < 0)
+                       goto out;
+       }
+       ret = para_printf(b, "\n");
+out:
+       osl_close_disk_object(&chunk_table_obj);
+       return ret;
+}
+
 static int print_list_item(struct ls_data *d, struct ls_options *opts,
        struct para_buffer *b, time_t current_time)
 {
@@ -836,10 +872,10 @@ static int print_list_item(struct ls_data *d, struct ls_options *opts,
        char asc_hash[2 * HASH_SIZE + 1];
        char *att_lines, *lyrics_lines, *image_lines, *filename_lines;
 
-       if (opts->mode == LS_MODE_SHORT) {
-               para_printf(b, "%s\n", d->path);
-               return 1;
-       }
+       if (opts->mode == LS_MODE_SHORT)
+               return para_printf(b, "%s\n", d->path);
+       if (opts->mode == LS_MODE_CHUNKS)
+               return print_chunk_table(d, b);
        get_attribute_bitmap(&afsi->attributes, att_buf);
        ret = get_local_time(&afsi->last_played, last_played_time,
                sizeof(last_played_time), current_time, opts->mode);
@@ -854,7 +890,7 @@ static int print_list_item(struct ls_data *d, struct ls_options *opts,
        }
 
        if (opts->mode == LS_MODE_LONG) {
-               para_printf(b,
+               return para_printf(b,
                        "%s"    /* score */
                        "%s "   /* attributes */
                        "%*d "  /* image_id  */
@@ -880,95 +916,78 @@ static int print_list_item(struct ls_data *d, struct ls_options *opts,
                        last_played_time,
                        d->path
                );
-               return 1;
        }
        hash_to_asc(d->hash, asc_hash);
        att_lines = make_attribute_lines(att_buf, afsi);
        lyrics_lines = make_lyrics_lines(afsi);
        image_lines = make_image_lines(afsi);
        filename_lines = make_filename_lines(d->path, opts->flags);
-       if (opts->mode == LS_MODE_VERBOSE) {
-               para_printf(b,
-                       "%s" /* filename stuff */
-                       "%s%s%s%s" /* score */
-                       "%s\n" /* attributes */
-                       "%s: %s\n" /* hash */
-                       "%s" /* image id, image name */
-                       "%s" /* lyrics */
-                       "%s: %dkbit/s\n" /* bitrate */
-                       "%s: %s\n" /* format */
-                       "%s: %dHz\n" /* frequency */
-                       "%s: %d\n" /* channels */
-                       "%s: %s\n" /* duration */
-                       "%s: %lu\n" /* seconds total */
-                       "%s: %d\n" /* num_played */
-                       "%s: %s\n" /* last_played */
-                       "%s", /* tag info */
-                       filename_lines,
-                       have_score? status_item_list[SI_SCORE] : "",
-                               have_score? ": " : "",
-                               score_buf,
-                               have_score? "\n" : "",
-                       att_lines,
-                       status_item_list[SI_HASH], asc_hash,
-                       image_lines,
-                       lyrics_lines,
-                       status_item_list[SI_BITRATE], afhi->bitrate,
-                       status_item_list[SI_FORMAT], audio_format_name(afsi->audio_format_id),
-                       status_item_list[SI_FREQUENCY], afhi->frequency,
-                       status_item_list[SI_CHANNELS], afhi->channels,
-                       status_item_list[SI_DURATION], duration_buf,
-                       status_item_list[SI_SECONDS_TOTAL], afhi->seconds_total,
-                       status_item_list[SI_NUM_PLAYED], afsi->num_played,
-                       status_item_list[SI_LAST_PLAYED], last_played_time,
-                       afhi->info_string
-               );
-       } else { /* mbox mode */ /* FIXME: merge with verbose output */
-               struct osl_object lyrics_def;
-               lyr_get_def_by_id(afsi->lyrics_id, &lyrics_def);
-               para_printf(b,
+       if (opts->mode == LS_MODE_MBOX) {
+               const char *bn = para_basename(d->path);
+               ret = para_printf(b,
                        "From foo@localhost %s\n"
                        "Received: from\nTo: bar\nFrom: a\n"
-                       "Subject: %s\n\n" /* path */
-                       "%s%s%s" /* score */
-                       "%s\n" /* attributes */
-                       "hash: %s\n"
-                       "%s\n" /* image id, image name */
-                       "lyrics_id: %s\n"
-                       "bitrate: %dkbit/s\n"
-                       "format: %s\n"
-                       "frequency: %dHz\n"
-                       "channels: %d\n"
-                       "duration: %s\n"
-                       "num_played: %d\n"
-                       "%s\n" /* tag info */
-                       "%s%s\n",
+                       "Subject: %s\n\n",
                        last_played_time,
-                       d->path,
-                       have_score? "score: " : "", score_buf,
-                               have_score? "\n" : "",
-                       att_lines,
-                       asc_hash,
-                       image_lines,
-                       lyrics_lines,
-                       afhi->bitrate,
-                       audio_format_name(afsi->audio_format_id),
-                       afhi->frequency,
-                       afhi->channels,
-                       duration_buf,
-                       afsi->num_played,
-                       afhi->info_string,
-                       lyrics_def.data? "Lyrics:\n~~~~~~~\n" : "",
-                       lyrics_def.data? (char *)lyrics_def.data : ""
-               );
-               if (lyrics_def.data)
+                       bn? bn : "?");
+               if (ret < 0)
+                       return ret;
+       }
+       ret = para_printf(b,
+               "%s" /* filename stuff */
+               "%s%s%s%s" /* score */
+               "%s\n" /* attributes */
+               "%s: %s\n" /* hash */
+               "%s" /* image id, image name */
+               "%s" /* lyrics */
+               "%s: %dkbit/s\n" /* bitrate */
+               "%s: %s\n" /* format */
+               "%s: %dHz\n" /* frequency */
+               "%s: %d\n" /* channels */
+               "%s: %s\n" /* duration */
+               "%s: %lu\n" /* seconds total */
+               "%s: %s\n" /* last played time */
+               "%s: %d\n" /* num_played */
+               "%s" /* tag info */
+               "%s: %lu\n" /* chunk time */
+               "%s: %lu\n", /* num chunks */
+               filename_lines,
+               have_score? status_item_list[SI_SCORE] : "",
+                       have_score? ": " : "",
+                       score_buf,
+                       have_score? "\n" : "",
+               att_lines,
+               status_item_list[SI_HASH], asc_hash,
+               image_lines,
+               lyrics_lines,
+               status_item_list[SI_BITRATE], afhi->bitrate,
+               status_item_list[SI_FORMAT], audio_format_name(afsi->audio_format_id),
+               status_item_list[SI_FREQUENCY], afhi->frequency,
+               status_item_list[SI_CHANNELS], afhi->channels,
+               status_item_list[SI_DURATION], duration_buf,
+               status_item_list[SI_SECONDS_TOTAL], afhi->seconds_total,
+               status_item_list[SI_LAST_PLAYED], last_played_time,
+               status_item_list[SI_NUM_PLAYED], afsi->num_played,
+               afhi->info_string,
+               status_item_list[SI_CHUNK_TIME], tv2ms(&afhi->chunk_tv),
+               status_item_list[SI_NUM_CHUNKS], afhi->chunks_total
+       );
+       if (ret < 0)
+               return ret;
+       if (opts->mode == LS_MODE_MBOX) {
+               struct osl_object lyrics_def;
+               lyr_get_def_by_id(afsi->lyrics_id, &lyrics_def);
+               if (lyrics_def.data) {
+                       ret = para_printf(b, "Lyrics:\n~~~~~~~\n%s",
+                               (char *)lyrics_def.data);
                        osl_close_disk_object(&lyrics_def);
+               }
        }
        free(att_lines);
        free(lyrics_lines);
        free(image_lines);
        free(filename_lines);
-       return 1;
+       return ret;
 }
 
 void make_empty_status_items(char *buf)
@@ -978,7 +997,7 @@ void make_empty_status_items(char *buf)
                "%s: \n" /* dirname */
                "%s: \n" /* basename */
                "%s: \n" /* score */
-               "%s: \n" /* attributes bitnmap */
+               "%s: \n" /* attributes bitmap */
                "%s: \n" /* attributes txt */
                "%s: \n" /* hash */
                "%s: \n" /* image id */
@@ -1226,12 +1245,12 @@ static int prepare_ls_row(struct osl_row *row, void *ls_opts)
        return 1;
 }
 
-static int com_ls_callback(const struct osl_object *query,
-               struct osl_object *ls_output)
+static void com_ls_callback(int fd, const struct osl_object *query)
 {
        struct ls_options *opts = query->data;
        char *p, *pattern_start = (char *)query->data + sizeof(*opts);
-       struct para_buffer b = {.buf = NULL, .size = 0};
+       struct para_buffer b = {.max_size = SHMMAX,
+               .max_size_handler = pass_buffer_as_shm, .private_data = &fd};
        int i = 0, ret;
        time_t current_time;
 
@@ -1262,22 +1281,21 @@ static int com_ls_callback(const struct osl_object *query,
                for (i = opts->num_matching_paths - 1; i >= 0; i--) {
                        ret = print_list_item(opts->data_ptr[i], opts, &b, current_time);
                        if (ret < 0)
-                               break;
+                               goto out;
                }
        else
                for (i = 0; i < opts->num_matching_paths; i++) {
                        ret = print_list_item(opts->data_ptr[i], opts, &b, current_time);
                        if (ret < 0)
-                               break;
+                               goto out;
                }
-       ret = 1;
 out:
-       ls_output->data = b.buf;
-       ls_output->size = b.size;
+       if (b.offset)
+               pass_buffer_as_shm(b.buf, b.offset, &fd);
+       free(b.buf);
        free(opts->data);
        free(opts->data_ptr);
        free(opts->patterns);
-       return ret;
 }
 
 /*
@@ -1290,8 +1308,7 @@ int com_ls(int fd, int argc, char * const * const argv)
        enum ls_sorting_method sort = LS_SORT_BY_PATH;
        enum ls_listing_mode mode = LS_MODE_SHORT;
        struct ls_options opts = {.patterns = NULL};
-       struct osl_object query = {.data = &opts, .size = sizeof(opts)},
-               ls_output;
+       struct osl_object query = {.data = &opts, .size = sizeof(opts)};
 
        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
@@ -1321,6 +1338,9 @@ int com_ls(int fd, int argc, char * const * const argv)
                        case 'm':
                                mode = LS_MODE_MBOX;
                                continue;
+                       case 'c':
+                               mode = LS_MODE_CHUNKS;
+                               continue;
                        default:
                                return -E_AFT_SYNTAX;
                        }
@@ -1386,11 +1406,7 @@ int com_ls(int fd, int argc, char * const * const argv)
        opts.mode = mode;
        opts.num_patterns = argc - i;
        ret = send_option_arg_callback_request(&query, opts.num_patterns,
-               argv + i, com_ls_callback, &ls_output);
-       if (ret > 0) {
-               ret = send_buffer(fd, (char *)ls_output.data);
-               free(ls_output.data);
-       }
+               argv + i, com_ls_callback, send_result, &fd);
        return ret;
 }
 
@@ -1417,88 +1433,111 @@ static struct osl_row *find_hash_sister(HASH_TYPE *hash)
        return row;
 }
 
-enum aft_row_offsets {
-       AFTROW_AFHI_OFFSET_POS = 0,
-       AFTROW_CHUNKS_OFFSET_POS = 2,
-       AFTROW_AUDIO_FORMAT_OFFSET = 4,
-       AFTROW_FLAGS_OFFSET = 5,
-       AFTROW_HASH_OFFSET = 9,
-       AFTROW_PATH_OFFSET = (AFTROW_HASH_OFFSET + HASH_SIZE),
+/** The format of the data stored by save_audio_file_data(). */
+enum com_add_buffer_offsets {
+       /** afhi (if present) starts here. */
+       CAB_AFHI_OFFSET_POS = 0,
+       /** Start of the chunk table (if present). */
+       CAB_CHUNKS_OFFSET_POS = 2,
+       /** Audio format id. */
+       CAB_AUDIO_FORMAT_OFFSET = 4,
+       /** Flags given to the add command. */
+       CAB_FLAGS_OFFSET = 5,
+       /** The hash of the audio file being added. */
+       CAB_HASH_OFFSET = 9,
+       /** Start of the path of the audio file. */
+       CAB_PATH_OFFSET = (CAB_HASH_OFFSET + HASH_SIZE),
 };
 
-/* never save the afsi, as the server knows it too. Note that afhi might be NULL.
- * In this case, afhi won't be stored in the buffer  */
-static void save_audio_file_info(HASH_TYPE *hash, const char *path,
+/*
+ * Store the given data to a single buffer. Doesn't need the audio file selector
+ * info struct as the server knows it as well.
+ *
+ * It's OK to call this with afhi == NULL. In this case, the audio format
+ * handler info won't be stored in the buffer.
+ */
+static void save_add_callback_buffer(HASH_TYPE *hash, const char *path,
                struct afh_info *afhi, uint32_t flags,
                uint8_t audio_format_num, struct osl_object *obj)
 {
        size_t path_len = strlen(path) + 1;
        size_t afhi_size = sizeof_afhi_buf(afhi);
-       size_t size = AFTROW_PATH_OFFSET + path_len + afhi_size
+       size_t size = CAB_PATH_OFFSET + path_len + afhi_size
                + sizeof_chunk_table(afhi);
        char *buf = para_malloc(size);
        uint16_t pos;
 
-       write_u8(buf + AFTROW_AUDIO_FORMAT_OFFSET, audio_format_num);
-       write_u32(buf + AFTROW_FLAGS_OFFSET, flags);
+       write_u8(buf + CAB_AUDIO_FORMAT_OFFSET, audio_format_num);
+       write_u32(buf + CAB_FLAGS_OFFSET, flags);
 
-       memcpy(buf + AFTROW_HASH_OFFSET, hash, HASH_SIZE);
-       strcpy(buf + AFTROW_PATH_OFFSET, path);
+       memcpy(buf + CAB_HASH_OFFSET, hash, HASH_SIZE);
+       strcpy(buf + CAB_PATH_OFFSET, path);
 
-       pos = AFTROW_PATH_OFFSET + path_len;
+       pos = CAB_PATH_OFFSET + path_len;
        PARA_DEBUG_LOG("size: %zu, afhi starts at %d\n", size, pos);
        PARA_DEBUG_LOG("last afhi byte: %p, pos %zu\n", buf + pos + afhi_size - 1,
                pos + afhi_size - 1);
-       write_u16(buf + AFTROW_AFHI_OFFSET_POS, pos);
+       write_u16(buf + CAB_AFHI_OFFSET_POS, pos);
        save_afhi(afhi, buf + pos);
 
        pos += afhi_size;
        PARA_DEBUG_LOG("size: %zu, chunks start at %d\n", size, pos);
-       write_u16(buf + AFTROW_CHUNKS_OFFSET_POS, pos);
-       save_chunk_table(afhi, buf + pos);
+       write_u16(buf + CAB_CHUNKS_OFFSET_POS, pos);
+       if (afhi)
+               save_chunk_table(afhi, buf + pos);
        PARA_DEBUG_LOG("last byte in buf: %p\n", buf + size - 1);
        obj->data = buf;
        obj->size = size;
 }
 
 /*
-input:
+
+Overview of the add command.
+
+Input: What was passed to the callback by the command handler.
 ~~~~~~
-HS:    hash sister
-PB:    path brother
-F:     force flag given
+HS:    Hash sister. Whether an audio file with identical hash
+       already exists in the osl database.
+
+PB:    Path brother. Whether a file with the given path exists
+       in the table.
 
-output:
+F:     Force flag given. Whether add was called with -f.
+
+output: Action performed by the callback.
 ~~~~~~~
-AFHI:  whether afhi and chunk table are computed and sent
-ACTION:        table modifications to be performed
-
-+---+----+-----+------+---------------------------------------------------+
-| HS | PB | F  | AFHI | ACTION
-+---+----+-----+------+---------------------------------------------------+
-| Y |  Y |  Y  |  Y   | if HS != PB: remove PB. HS: force afhi update,
-|                     | update path, keep afsi
-+---+----+-----+------+---------------------------------------------------+
-| Y |  Y |  N  |  N   | if HS == PB: do not send callback request at all.
-|                     | otherwise: remove PB, HS: update path, keep afhi,
-|                     | afsi.
-+---+----+-----+------+---------------------------------------------------+
-| Y |  N |  Y  |  Y   | (rename) force afhi update of HS, update path of
-|                     | HS, keep afsi
-+---+----+-----+------+---------------------------------------------------+
-| Y |  N |  N  |  N   | (file rename) update path of HS, keep afsi, afhi
-+---+----+-----+------+---------------------------------------------------+
-| N |  Y |  Y  |  Y   | (file change) update afhi, hash, of PB, keep afsi
-|                     | (force has no effect)
-+---+----+-----+------+---------------------------------------------------+
-| N |  Y |  N  |  Y   | (file change) update afhi, hash of PB, keep afsi
-+---+----+-----+------+---------------------------------------------------+
-| N |  N |  Y  |  Y   | (new file) create new entry (force has no effect)
-+---+----+-----+------+---------------------------------------------------+
-| N |  N |  N  |  Y   | (new file) create new entry
-+---+----+-----+------+---------------------------------------------------+
-
-afhi <=> force or no HS
+AFHI:  Whether afhi and chunk table are computed and sent.
+ACTION:        Table modifications to be done by the callback.
+
++----+----+---+------+---------------------------------------------------+
+| HS | PB | F | AFHI | ACTION
++----+----+---+------+---------------------------------------------------+
+| Y  |  Y | Y |  Y   | if HS != PB: remove PB. HS: force afhi update,
+|                    | update path, keep afsi
++----+----+---+------+---------------------------------------------------+
+| Y  |  Y | N |  N   | if HS == PB: do not send callback request at all.
+|                    | otherwise: remove PB, HS: update path, keep afhi,
+|                    | afsi.
++----+----+---+------+---------------------------------------------------+
+| Y  |  N | Y |  Y   | (rename) force afhi update of HS, update path of
+|                    | HS, keep afsi
++----+----+---+------+---------------------------------------------------+
+| Y  |  N | N |  N   | (file rename) update path of HS, keep afsi, afhi
++----+----+---+------+---------------------------------------------------+
+| N  |  Y | Y |  Y   | (file change) update afhi, hash, of PB, keep afsi
+|                    | (force has no effect)
++----+----+---+------+---------------------------------------------------+
+| N  |  Y | N |  Y   | (file change) update afhi, hash of PB, keep afsi
++----+----+---+------+---------------------------------------------------+
+| N  |  N | Y |  Y   | (new file) create new entry (force has no effect)
++----+----+---+------+---------------------------------------------------+
+|  N |  N | N |  Y   | (new file) create new entry
++----+----+---+------+---------------------------------------------------+
+
+Notes:
+
+       afhi <=> force or no HS
+       F => AFHI
 
 */
 
@@ -1514,8 +1553,7 @@ enum com_add_flags {
        ADD_FLAG_ALL = 8,
 };
 
-static int com_add_callback(const struct osl_object *query,
-               struct osl_object *result)
+static void com_add_callback(int fd, const struct osl_object *query)
 {
        char *buf = query->data, *path;
        struct osl_row *pb, *aft_row;
@@ -1525,16 +1563,17 @@ static int com_add_callback(const struct osl_object *query,
        char asc[2 * HASH_SIZE + 1];
        int ret;
        char afsi_buf[AFSI_SIZE];
-       uint32_t flags = read_u32(buf + AFTROW_FLAGS_OFFSET);
+       uint32_t flags = read_u32(buf + CAB_FLAGS_OFFSET);
        struct afs_info default_afsi = {.last_played = 0};
-       struct para_buffer msg = {.buf = NULL};
+       struct para_buffer msg = {.max_size = SHMMAX,
+               .max_size_handler = pass_buffer_as_shm, .private_data = &fd};
 
-       hash = (HASH_TYPE *)buf + AFTROW_HASH_OFFSET;
+       hash = (HASH_TYPE *)buf + CAB_HASH_OFFSET;
        hash_to_asc(hash, asc);;
-       objs[AFTCOL_HASH].data = buf + AFTROW_HASH_OFFSET;
+       objs[AFTCOL_HASH].data = buf + CAB_HASH_OFFSET;
        objs[AFTCOL_HASH].size = HASH_SIZE;
 
-       path = buf + AFTROW_PATH_OFFSET;
+       path = buf + CAB_PATH_OFFSET;
        objs[AFTCOL_PATH].data = path;
        objs[AFTCOL_PATH].size = strlen(path) + 1;
 
@@ -1542,18 +1581,22 @@ static int com_add_callback(const struct osl_object *query,
        hs = find_hash_sister(hash);
        ret = aft_get_row_of_path(path, &pb);
        if (ret < 0 && ret != -E_RB_KEY_NOT_FOUND)
-               return ret;
+               goto out;
        if (hs && pb && hs == pb && !(flags & ADD_FLAG_FORCE)) {
                if (flags & ADD_FLAG_VERBOSE)
-                       para_printf(&msg, "ignoring duplicate\n");
-               ret = 1;
+                       ret = para_printf(&msg, "ignoring duplicate\n");
+               else
+                       ret = 1;
                goto out;
        }
        if (hs && hs != pb) {
                struct osl_object obj;
                if (pb) { /* hs trumps pb, remove pb */
-                       if (flags & ADD_FLAG_VERBOSE)
-                               para_printf(&msg, "removing path brother\n");
+                       if (flags & ADD_FLAG_VERBOSE) {
+                               ret = para_printf(&msg, "removing path brother\n");
+                               if (ret < 0)
+                                       goto out;
+                       }
                        ret = osl_del_row(audio_file_table, pb);
                        if (ret < 0)
                                goto out;
@@ -1565,7 +1608,9 @@ static int com_add_callback(const struct osl_object *query,
                                AFTCOL_PATH, &obj);
                        if (ret < 0)
                                goto out;
-                       para_printf(&msg, "renamed from %s\n", (char *)obj.data);
+                       ret = para_printf(&msg, "renamed from %s\n", (char *)obj.data);
+                       if (ret < 0)
+                               goto out;
                }
                ret = osl_update_object(audio_file_table, hs, AFTCOL_PATH,
                        &objs[AFTCOL_PATH]);
@@ -1576,8 +1621,8 @@ static int com_add_callback(const struct osl_object *query,
                        goto out;
        }
        /* no hs or force mode, child must have sent afhi */
-       uint16_t afhi_offset = read_u16(buf + AFTROW_AFHI_OFFSET_POS);
-       uint16_t chunks_offset = read_u16(buf + AFTROW_CHUNKS_OFFSET_POS);
+       uint16_t afhi_offset = read_u16(buf + CAB_AFHI_OFFSET_POS);
+       uint16_t chunks_offset = read_u16(buf + CAB_CHUNKS_OFFSET_POS);
 
        objs[AFTCOL_AFHI].data = buf + afhi_offset;
        objs[AFTCOL_AFHI].size = chunks_offset - afhi_offset;
@@ -1593,9 +1638,12 @@ static int com_add_callback(const struct osl_object *query,
                if (ret < 0)
                        goto out;
                hash_to_asc(old_hash, old_asc);
-               if (flags & ADD_FLAG_VERBOSE)
-                       para_printf(&msg, "file change: %s -> %s\n",
+               if (flags & ADD_FLAG_VERBOSE) {
+                       ret = para_printf(&msg, "file change: %s -> %s\n",
                                old_asc, asc);
+                       if (ret < 0)
+                               goto out;
+               }
                ret = osl_update_object(audio_file_table, pb, AFTCOL_HASH,
                        &objs[AFTCOL_HASH]);
                if (ret < 0)
@@ -1604,8 +1652,11 @@ static int com_add_callback(const struct osl_object *query,
        if (hs || pb) { /* (hs != NULL and pb != NULL) implies hs == pb */
                struct osl_row *row = pb? pb : hs;
                /* update afhi and chunk_table */
-               if (flags & ADD_FLAG_VERBOSE)
-                       para_printf(&msg, "updating afhi and chunk table\n");
+               if (flags & ADD_FLAG_VERBOSE) {
+                       ret = para_printf(&msg, "updating afhi and chunk table\n");
+                       if (ret < 0)
+                               goto out;
+               }
                ret = osl_update_object(audio_file_table, row, AFTCOL_AFHI,
                        &objs[AFTCOL_AFHI]);
                if (ret < 0)
@@ -1618,10 +1669,13 @@ static int com_add_callback(const struct osl_object *query,
                goto out;
        }
        /* new entry, use default afsi */
-       if (flags & ADD_FLAG_VERBOSE)
-               para_printf(&msg, "new file\n");
+       if (flags & ADD_FLAG_VERBOSE) {
+               ret = para_printf(&msg, "new file\n");
+               if (ret < 0)
+                       goto out;
+       }
        default_afsi.last_played = time(NULL) - 365 * 24 * 60 * 60;
-       default_afsi.audio_format_id = read_u8(buf + AFTROW_AUDIO_FORMAT_OFFSET);
+       default_afsi.audio_format_id = read_u8(buf + CAB_AUDIO_FORMAT_OFFSET);
 
        objs[AFTCOL_AFSI].data = &afsi_buf;
        objs[AFTCOL_AFSI].size = AFSI_SIZE;
@@ -1630,12 +1684,10 @@ static int com_add_callback(const struct osl_object *query,
        afs_event(AUDIO_FILE_ADD, &msg, aft_row);
 out:
        if (ret < 0)
-               para_printf(&msg, "%s\n", PARA_STRERROR(-ret));
-       if (!msg.buf)
-               return 0;
-       result->data = msg.buf;
-       result->size = msg.size;
-       return 1;
+               ret = para_printf(&msg, "%s\n", para_strerror(-ret));
+       if (msg.offset)
+               pass_buffer_as_shm(msg.buf, msg.offset, &fd);
+       free(msg.buf);
 }
 
 /** Used by com_add(). */
@@ -1646,63 +1698,57 @@ struct private_add_data {
        uint32_t flags;
 };
 
-static int path_brother_callback(const struct osl_object *query,
-               struct osl_object *result)
+static void path_brother_callback(int fd, const struct osl_object *query)
 {
        char *path = query->data;
        struct osl_row *path_brother;
        int ret = aft_get_row_of_path(path, &path_brother);
        if (ret < 0)
-               return ret;
-       result->data = para_malloc(sizeof(path_brother));
-       result->size = sizeof(path_brother);
-       *(struct osl_row **)(result->data) = path_brother;
-       return 1;
+               return;
+       pass_buffer_as_shm((char *)&path_brother, sizeof(path_brother), &fd);
 }
 
-static int hash_sister_callback(const struct osl_object *query,
-               struct osl_object *result)
+static void hash_sister_callback(int fd, const struct osl_object *query)
 {
        HASH_TYPE *hash = query->data;
        struct osl_row *hash_sister;
 
        hash_sister = find_hash_sister(hash);
        if (!hash_sister)
-               return -E_RB_KEY_NOT_FOUND;
-       result->data = para_malloc(sizeof(hash_sister));
-       result->size = sizeof(hash_sister);
-       *(struct osl_row **)(result->data) = hash_sister;
+               return;
+       pass_buffer_as_shm((char *)&hash_sister, sizeof(hash_sister), &fd);
+}
+
+static int get_row_pointer_from_result(struct osl_object *result, void *private)
+{
+       struct osl_row **row = private;
+       *row = result->data;
        return 1;
 }
 
-static int add_one_audio_file(const char *path, const void *private_data)
+static int add_one_audio_file(const char *path, void *private_data)
 {
-       int ret, ret2;
+       int ret, send_ret = 1;
        uint8_t format_num = -1;
-       const struct private_add_data *pad = private_data;
+       struct private_add_data *pad = private_data;
        struct afh_info afhi, *afhi_ptr = NULL;
        struct osl_row *pb = NULL, *hs = NULL; /* path brother/hash sister */
-       struct osl_object map, obj = {.data = NULL}, query, result = {.data = NULL};
+       struct osl_object map, obj = {.data = NULL}, query;
        HASH_TYPE hash[HASH_SIZE];
 
-       afhi.header_offset = 0;
-       afhi.header_len = 0;
        ret = guess_audio_format(path);
        if (ret < 0 && !(pad->flags & ADD_FLAG_ALL))
                goto out_free;
        query.data = (char *)path;
        query.size = strlen(path) + 1;
-       ret = send_callback_request(path_brother_callback, &query, &result);
+       ret = send_callback_request(path_brother_callback, &query,
+               get_row_pointer_from_result, &pb);
        if (ret < 0 && ret != -E_RB_KEY_NOT_FOUND)
                goto out_free;
-       if (ret >= 0) {
-               pb = *(struct osl_row **)result.data;
-               free(result.data);
-       }
        ret = 1;
        if (pb && (pad->flags & ADD_FLAG_LAZY)) { /* lazy is really cheap */
                if (pad->flags & ADD_FLAG_VERBOSE)
-                       ret = send_va_buffer(pad->fd, "lazy-ignore: %s\n", path);
+                       send_ret = send_va_buffer(pad->fd, "lazy-ignore: %s\n", path);
                goto out_free;
        }
        /* We still want to add this file. Compute its hash. */
@@ -1711,27 +1757,24 @@ static int add_one_audio_file(const char *path, const void *private_data)
                goto out_free;
        hash_function(map.data, map.size, hash);
 
-       /* Check whether database contains file with the same hash. */
+       /* Check whether the database contains a file with the same hash. */
        query.data = hash;
        query.size = HASH_SIZE;
-       ret = send_callback_request(hash_sister_callback, &query, &result);
-       if (ret < 0 && ret != -E_RB_KEY_NOT_FOUND)
-               goto out_free;
-       if (ret >= 0) {
-               hs = *(struct osl_row **)result.data;
-               free(result.data);
-       }
+       ret = send_callback_request(hash_sister_callback, &query,
+               get_row_pointer_from_result, &hs);
+       if (ret < 0)
+               goto out_unmap;
        /* Return success if we already know this file. */
        ret = 1;
-       if (pb && hs && hs == pb && (!(pad->flags & ADD_FLAG_FORCE))) {
+       if (pb && hs && hs == pb && !(pad->flags & ADD_FLAG_FORCE)) {
                if (pad->flags & ADD_FLAG_VERBOSE)
-                       ret = send_va_buffer(pad->fd,
+                       send_ret = send_va_buffer(pad->fd,
                                "%s exists, not forcing update\n", path);
                goto out_unmap;
        }
        /*
-        * we won't recalculate the audio format info and the chunk table if
-        * there is a hash sister unless in FORCE mode.
+        * We won't recalculate the audio format info and the chunk table if
+        * there is a hash sister and FORCE was not given.
         */
        if (!hs || (pad->flags & ADD_FLAG_FORCE)) {
                ret = compute_afhi(path, map.data, map.size, &afhi);
@@ -1740,34 +1783,28 @@ static int add_one_audio_file(const char *path, const void *private_data)
                format_num = ret;
                afhi_ptr = &afhi;
        }
+       munmap(map.data, map.size);
        if (pad->flags & ADD_FLAG_VERBOSE) {
-               ret = send_va_buffer(pad->fd, "adding %s\n", path);
-               if (ret < 0)
-                       goto out_unmap;
+               send_ret = send_va_buffer(pad->fd, "adding %s\n", path);
+               if (send_ret < 0)
+                       goto out_free;
        }
-       munmap(map.data, map.size);
-       save_audio_file_info(hash, path, afhi_ptr, pad->flags, format_num, &obj);
+       save_add_callback_buffer(hash, path, afhi_ptr, pad->flags, format_num, &obj);
        /* Ask afs to consider this entry for adding. */
-       ret = send_callback_request(com_add_callback, &obj, &result);
-       if (ret > 0) {
-               ret2 = send_va_buffer(pad->fd, "%s", (char *)result.data);
-               free(result.data);
-               if (ret >= 0 && ret2 < 0)
-                       ret = ret2;
-       }
+       ret = send_callback_request(com_add_callback, &obj, send_result, &pad->fd);
        goto out_free;
 
 out_unmap:
        munmap(map.data, map.size);
 out_free:
-       if (ret < 0 && ret != -E_SEND)
-               send_va_buffer(pad->fd, "failed to add %s (%s)\n", path,
-                       PARA_STRERROR(-ret));
+       if (ret < 0 && send_ret >= 0)
+               send_ret = send_va_buffer(pad->fd, "failed to add %s (%s)\n", path,
+                       para_strerror(-ret));
        free(obj.data);
        if (afhi_ptr)
                free(afhi_ptr->chunk_table);
-       /* it's not an error if not all files could be added */
-       return ret == -E_SEND? ret : 1;
+       /* Stop adding files only on send errors. */
+       return send_ret;
 }
 
 int com_add(int fd, int argc, char * const * const argv)
@@ -1807,7 +1844,8 @@ int com_add(int fd, int argc, char * const * const argv)
                char *path;
                ret = verify_path(argv[i], &path);
                if (ret < 0) {
-                       ret = send_va_buffer(fd, "%s: %s\n", argv[i], PARA_STRERROR(-ret));
+                       ret = send_va_buffer(fd, "%s: %s\n", argv[i],
+                               para_strerror(-ret));
                        if (ret < 0)
                                return ret;
                        continue;
@@ -1827,7 +1865,7 @@ int com_add(int fd, int argc, char * const * const argv)
                else
                        ret = add_one_audio_file(path, &pad);
                if (ret < 0) {
-                       send_va_buffer(fd, "%s: %s\n", path, PARA_STRERROR(-ret));
+                       send_va_buffer(fd, "%s: %s\n", path, para_strerror(-ret));
                        free(path);
                        return ret;
                }
@@ -1869,6 +1907,8 @@ struct touch_action_data {
        struct com_touch_options *cto;
        /** Message buffer. */
        struct para_buffer pb;
+       /** How many audio files matched the given pattern. */
+       unsigned num_matches;
 };
 
 static int touch_audio_file(__a_unused struct osl_table *table,
@@ -1882,26 +1922,28 @@ static int touch_audio_file(__a_unused struct osl_table *table,
        struct afsi_change_event_data aced;
 
        ret = get_afsi_object_of_row(row, &obj);
-       if (ret < 0) {
-               para_printf(&tad->pb, "%s: %s\n", name, PARA_STRERROR(-ret));
-               return 1;
-       }
+       if (ret < 0)
+               return para_printf(&tad->pb, "%s: %s\n", name, para_strerror(-ret));
        ret = load_afsi(&old_afsi, &obj);
-       if (ret < 0) {
-               para_printf(&tad->pb, "%s: %s\n", name, PARA_STRERROR(-ret));
-               return 1;
-       }
+       if (ret < 0)
+               return para_printf(&tad->pb, "%s: %s\n", name, para_strerror(-ret));
        new_afsi = old_afsi;
        if (no_options) {
                new_afsi.num_played++;
                new_afsi.last_played = time(NULL);
-               if (tad->cto->flags & TOUCH_FLAG_VERBOSE)
-                       para_printf(&tad->pb, "%s: num_played = %u, "
+               if (tad->cto->flags & TOUCH_FLAG_VERBOSE) {
+                       ret = para_printf(&tad->pb, "%s: num_played = %u, "
                                "last_played = now()\n", name,
                                new_afsi.num_played);
+                       if (ret < 0)
+                               return ret;
+               }
        } else {
-               if (tad->cto->flags & TOUCH_FLAG_VERBOSE)
-                       para_printf(&tad->pb, "touching %s\n", name);
+               if (tad->cto->flags & TOUCH_FLAG_VERBOSE) {
+                       ret = para_printf(&tad->pb, "touching %s\n", name);
+                       if (ret < 0)
+                               return ret;
+               }
                if (tad->cto->lyrics_id >= 0)
                        new_afsi.lyrics_id = tad->cto->lyrics_id;
                if (tad->cto->image_id >= 0)
@@ -1911,6 +1953,7 @@ static int touch_audio_file(__a_unused struct osl_table *table,
                if (tad->cto->last_played >= 0)
                        new_afsi.last_played = tad->cto->last_played;
        }
+       tad->num_matches++;
        save_afsi(&new_afsi, &obj); /* in-place update */
        aced.aft_row = row;
        aced.old_afsi = &old_afsi;
@@ -1918,11 +1961,16 @@ static int touch_audio_file(__a_unused struct osl_table *table,
        return 1;
 }
 
-static int com_touch_callback(const struct osl_object *query,
-               struct osl_object *result)
+static void com_touch_callback(int fd, const struct osl_object *query)
 {
-       struct touch_action_data tad = {.cto = query->data};
-       int ret;
+       struct touch_action_data tad = {.cto = query->data,
+               .pb = {
+                       .max_size = SHMMAX,
+                       .private_data = &fd,
+                       .max_size_handler = pass_buffer_as_shm
+               }
+       };
+       int ret, ret2 = 0;
        struct pattern_match_data pmd = {
                .table = audio_file_table,
                .loop_col_num = AFTCOL_HASH,
@@ -1936,13 +1984,13 @@ static int com_touch_callback(const struct osl_object *query,
                pmd.fnmatch_flags |= FNM_PATHNAME;
        ret = for_each_matching_row(&pmd);
        if (ret < 0)
-               para_printf(&tad.pb, "%s\n", PARA_STRERROR(-ret));
-       if (tad.pb.buf) {
-               result->data = tad.pb.buf;
-               result->size = tad.pb.size;
-               return 1;
-       }
-       return ret < 0? ret : 0;
+               ret2 = para_printf(&tad.pb, "%s\n", para_strerror(-ret));
+       else
+               if (!tad.num_matches)
+                       ret2 = para_printf(&tad.pb, "no matches\n");
+       if (ret2 >= 0 && tad.pb.offset)
+               pass_buffer_as_shm(tad.pb.buf, tad.pb.offset, &fd);
+       free(tad.pb.buf);
 }
 
 int com_touch(int fd, int argc, char * const * const argv)
@@ -1953,8 +2001,7 @@ int com_touch(int fd, int argc, char * const * const argv)
                .lyrics_id = -1,
                .image_id = -1
        };
-       struct osl_object query = {.data = &cto, .size = sizeof(cto)},
-               result;
+       struct osl_object query = {.data = &cto, .size = sizeof(cto)};
        int i, ret;
 
 
@@ -2003,12 +2050,9 @@ int com_touch(int fd, int argc, char * const * const argv)
        if (i >= argc)
                return -E_AFT_SYNTAX;
        ret = send_option_arg_callback_request(&query, argc - i,
-               argv + i, com_touch_callback, &result);
-       if (ret > 0) {
-               send_buffer(fd, (char *)result.data);
-               free(result.data);
-       } else if (ret < 0)
-               send_va_buffer(fd, "%s\n", PARA_STRERROR(-ret));
+               argv + i, com_touch_callback, send_result, &fd);
+       if (ret < 0)
+               send_va_buffer(fd, "%s\n", para_strerror(-ret));
        return ret;
 }
 
@@ -2036,23 +2080,32 @@ static int remove_audio_file(__a_unused struct osl_table *table,
                struct osl_row *row, const char *name, void *data)
 {
        struct com_rm_action_data *crd = data;
-       int ret;
+       int ret, ret2;
 
-       if (crd->flags & RM_FLAG_VERBOSE)
-               para_printf(&crd->pb, "removing %s\n", name);
+       if (crd->flags & RM_FLAG_VERBOSE) {
+               ret = para_printf(&crd->pb, "removing %s\n", name);
+               if (ret < 0)
+                       return ret;
+       }
        afs_event(AUDIO_FILE_REMOVE, &crd->pb, row);
        ret = osl_del_row(audio_file_table, row);
        if (ret < 0)
-               para_printf(&crd->pb, "%s: %s\n", name, PARA_STRERROR(-ret));
+               ret2 = para_printf(&crd->pb, "%s: %s\n", name,
+                       para_strerror(-ret));
        else
                crd->num_removed++;
-       return 1;
+       return ret;
 }
 
-static int com_rm_callback(const struct osl_object *query,
-               __a_unused struct osl_object *result)
+static void com_rm_callback(int fd, const struct osl_object *query)
 {
-       struct com_rm_action_data crd = {.flags = *(uint32_t *)query->data};
+       struct com_rm_action_data crd = {.flags = *(uint32_t *)query->data,
+               .pb = {
+                       .max_size = SHMMAX,
+                       .private_data = &fd,
+                       .max_size_handler = pass_buffer_as_shm
+               }
+       };
        int ret;
        struct pattern_match_data pmd = {
                .table = audio_file_table,
@@ -2066,28 +2119,26 @@ static int com_rm_callback(const struct osl_object *query,
        if (crd.flags & RM_FLAG_FNM_PATHNAME)
                pmd.fnmatch_flags |= FNM_PATHNAME;
        ret = for_each_matching_row(&pmd);
-       if (ret < 0)
-               para_printf(&crd.pb, "%s\n", PARA_STRERROR(-ret));
+       if (ret < 0) {
+               ret = para_printf(&crd.pb, "%s\n", para_strerror(-ret));
+               return;
+       }
        if (!crd.num_removed && !(crd.flags & RM_FLAG_FORCE))
-               para_printf(&crd.pb, "no matches -- nothing removed\n");
+               ret = para_printf(&crd.pb, "no matches -- nothing removed\n");
        else {
                if (crd.flags & RM_FLAG_VERBOSE)
-                       para_printf(&crd.pb, "removed %u files\n", crd.num_removed);
-       }
-       if (crd.pb.buf) {
-               result->data = crd.pb.buf;
-               result->size = crd.pb.size;
-               return 1;
+                       ret = para_printf(&crd.pb, "removed %u files\n", crd.num_removed);
        }
-       return ret < 0? ret : 0;
+       if (ret >= 0 && crd.pb.offset)
+               pass_buffer_as_shm(crd.pb.buf, crd.pb.offset, &fd);
+       free(crd.pb.buf);
 }
 
 /* TODO options: -r (recursive) */
 int com_rm(int fd, int argc,  char * const * const argv)
 {
        uint32_t flags = 0;
-       struct osl_object query = {.data = &flags, .size = sizeof(flags)},
-               result;
+       struct osl_object query = {.data = &flags, .size = sizeof(flags)};
        int i, ret;
 
        for (i = 1; i < argc; i++) {
@@ -2115,12 +2166,9 @@ int com_rm(int fd, int argc,  char * const * const argv)
        if (i >= argc)
                return -E_AFT_SYNTAX;
        ret = send_option_arg_callback_request(&query, argc - i, argv + i,
-               com_rm_callback, &result);
-       if (ret > 0) {
-               send_buffer(fd, (char *)result.data);
-               free(result.data);
-       } else if (ret < 0)
-               send_va_buffer(fd, "%s\n", PARA_STRERROR(-ret));
+               com_rm_callback, send_result, &fd);
+       if (ret < 0)
+               send_va_buffer(fd, "%s\n", para_strerror(-ret));
        return ret;
 }
 
@@ -2182,18 +2230,27 @@ static int copy_selector_info(__a_unused struct osl_table *table,
                target_afsi.attributes = cad->source_afsi.attributes;
        save_afsi(&target_afsi, &target_afsi_obj); /* in-place update */
        cad->num_copied++;
-       if (cad->flags & CPSI_FLAG_VERBOSE)
-               para_printf(&cad->pb, "copied afsi to %s\n", name);
+       if (cad->flags & CPSI_FLAG_VERBOSE) {
+               ret = para_printf(&cad->pb, "copied afsi to %s\n", name);
+               if (ret < 0)
+                       return ret;
+       }
        aced.aft_row = row;
        aced.old_afsi = &old_afsi;
        afs_event(AFSI_CHANGE, &cad->pb, &aced);
        return 1;
 }
 
-static int com_cpsi_callback(const struct osl_object *query,
-               struct osl_object *result)
+static void com_cpsi_callback(int fd, const struct osl_object *query)
 {
-       struct cpsi_action_data cad = {.flags = *(unsigned *)query->data};
+       struct cpsi_action_data cad = {
+               .flags = *(unsigned *)query->data,
+               .pb = {
+                       .max_size = SHMMAX,
+                       .private_data = &fd,
+                       .max_size_handler = pass_buffer_as_shm
+               }
+       };
        int ret;
        char *source_path = (char *)query->data + sizeof(cad.flags);
 
@@ -2213,29 +2270,25 @@ static int com_cpsi_callback(const struct osl_object *query,
        ret = for_each_matching_row(&pmd);
 out:
        if (ret < 0)
-               para_printf(&cad.pb, "%s\n", PARA_STRERROR(-ret));
-       if (cad.flags & CPSI_FLAG_VERBOSE) {
+               ret = para_printf(&cad.pb, "%s\n", para_strerror(-ret));
+       else if (cad.flags & CPSI_FLAG_VERBOSE) {
                if (cad.num_copied)
-                       para_printf(&cad.pb, "copied requested afsi from %s "
+                       ret = para_printf(&cad.pb, "copied requested afsi from %s "
                                "to %u files\n",
                                source_path, cad.num_copied);
                else
-                       para_printf(&cad.pb, "nothing copied\n");
+                       ret = para_printf(&cad.pb, "nothing copied\n");
        }
-       if (cad.pb.buf) {
-               result->data = cad.pb.buf;
-               result->size = cad.pb.size;
-               return 1;
-       }
-       return ret < 0? ret : 0;
+       if (cad.pb.offset)
+               pass_buffer_as_shm(cad.pb.buf, cad.pb.offset, &fd);
+       free(cad.pb.buf);
 }
 
 int com_cpsi(int fd, int argc,  char * const * const argv)
 {
        unsigned flags = 0;
        int i, ret;
-       struct osl_object options = {.data = &flags, .size = sizeof(flags)},
-               result;
+       struct osl_object options = {.data = &flags, .size = sizeof(flags)};
 
        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
@@ -2276,12 +2329,9 @@ int com_cpsi(int fd, int argc,  char * const * const argv)
        if (!(flags & ~CPSI_FLAG_VERBOSE)) /* no copy flags given */
                flags = ~(unsigned)CPSI_FLAG_VERBOSE | flags;
        ret = send_option_arg_callback_request(&options, argc - i, argv + i,
-               com_cpsi_callback, &result);
-       if (ret > 0) {
-               send_buffer(fd, (char *)result.data);
-               free(result.data);
-       } else
-               send_va_buffer(fd, "%s\n", PARA_STRERROR(-ret));
+               com_cpsi_callback, send_result, &fd);
+       if (ret < 0)
+               send_va_buffer(fd, "%s\n", para_strerror(-ret));
        return ret;
 }
 
@@ -2295,52 +2345,61 @@ static int check_audio_file(struct osl_row *row, void *data)
        struct afs_info afsi;
        char *blob_name;
 
-       if (ret < 0) {
-               para_printf(pb, "%s\n", PARA_STRERROR(-ret));
-               return 1;
-       }
-       if (stat(path, &statbuf) < 0)
-               para_printf(pb, "%s: stat error (%s)\n", path, strerror(errno));
-       else {
-               if (!S_ISREG(statbuf.st_mode))
-                       para_printf(pb, "%s: not a regular file\n", path);
+       if (ret < 0)
+               return para_printf(pb, "%s\n", para_strerror(-ret));
+       if (stat(path, &statbuf) < 0) {
+               ret = para_printf(pb, "%s: stat error (%s)\n", path, strerror(errno));
+               if (ret < 0)
+                       return ret;
+       } else {
+               if (!S_ISREG(statbuf.st_mode)) {
+                       ret = para_printf(pb, "%s: not a regular file\n", path);
+                       if (ret < 0)
+                               return ret;
+               }
        }
        ret = get_afsi_of_row(row, &afsi);
+       if (ret < 0)
+               return para_printf(pb, "%s: %s\n", path, para_strerror(-ret));
+       ret = lyr_get_name_by_id(afsi.lyrics_id, &blob_name);
        if (ret < 0) {
-               para_printf(pb, "%s: %s\n", path, PARA_STRERROR(-ret));
-               return 1;
+               ret = para_printf(pb, "%s lyrics id %u: %s\n", path, afsi.lyrics_id,
+                       para_strerror(-ret));
+               if (ret < 0)
+                       return ret;
        }
-       ret = lyr_get_name_by_id(afsi.lyrics_id, &blob_name);
-       if (ret < 0)
-               para_printf(pb, "%s lyrics id %u: %s\n", path, afsi.lyrics_id,
-                       PARA_STRERROR(-ret));
        ret = img_get_name_by_id(afsi.image_id, &blob_name);
        if (ret < 0)
-               para_printf(pb, "%s image id %u: %s\n", path, afsi.image_id,
-                       PARA_STRERROR(-ret));
-       return 1;
+               ret = para_printf(pb, "%s image id %u: %s\n", path, afsi.image_id,
+                       para_strerror(-ret));
+       return ret;
 }
 
 /**
  * Check the audio file table for inconsistencies.
  *
+ * \param fd The afs socket.
  * \param query Unused.
- * \param result Contains message string upon return.
  *
  * This function always succeeds.
  *
  * \sa com_check().
  */
-int aft_check_callback(__a_unused const struct osl_object *query, struct osl_object *result)
+void aft_check_callback(int fd, __a_unused const struct osl_object *query)
 {
-       struct para_buffer pb = {.buf = NULL};
+       struct para_buffer pb = {
+               .max_size = SHMMAX,
+               .private_data = &fd,
+               .max_size_handler = pass_buffer_as_shm
+       };
+       int ret = para_printf(&pb, "checking audio file table...\n");
 
-       para_printf(&pb, "checking audio file table...\n");
+       if (ret < 0)
+               return;
        audio_file_loop(&pb, check_audio_file);
-       result->data = pb.buf;
-       result->size = pb.size;
-       return 1;
-
+       if (pb.offset)
+               pass_buffer_as_shm(pb.buf, pb.offset, &fd);
+       free(pb.buf);
 }
 
 /**
@@ -2411,12 +2470,16 @@ static int clear_attribute(struct osl_row *row, void *data)
 static int aft_event_handler(enum afs_events event, struct para_buffer *pb,
                void *data)
 {
+       int ret;
+
        switch(event) {
        case ATTRIBUTE_REMOVE: {
                const struct rmatt_event_data *red = data;
-               para_printf(pb, "clearing attribute %s (bit %u) from all "
+               ret = para_printf(pb, "clearing attribute %s (bit %u) from all "
                        "entries in the audio file table\n", red->name,
                        red->bitnum);
+               if (ret < 0)
+                       return ret;
                return audio_file_loop(data, clear_attribute);
                }
        default: