mdw@git.distorted.org.uk Git - disorder/blob - lib/queue.c

   1 /*
   2  * This file is part of DisOrder.
   3  * Copyright (C) 2004-2008 Richard Kettlewell
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "common.h"
  20
  21 #include <errno.h>
  22 #include <stddef.h>
  23
  24 #include "mem.h"
  25 #include "queue.h"
  26 #include "log.h"
  27 #include "split.h"
  28 #include "syscalls.h"
  29 #include "table.h"
  30 #include "printf.h"
  31
  32 const char *playing_states[] = {
  33   "failed",
  34   "isscratch",
  35   "no_player",
  36   "ok",
  37   "paused",
  38   "quitting",
  39   "random",
  40   "scratched",
  41   "started",
  42   "unplayed"
  43 };
  44
  45 #define VALUE(q, offset, type) *(type *)((char *)q + offset)
  46
  47 /* add new entry @n@ to a doubly linked list just after @b@ */
  48 void queue_insert_entry(struct queue_entry *b, struct queue_entry *n) {
  49   n->prev = b;
  50   n->next = b->next;
  51   n->next->prev = n;
  52   n->prev->next = n;
  53 }
  54
  55 /* remove an entry from a doubly-linked list */
  56 void queue_delete_entry(struct queue_entry *node) {
  57   node->next->prev = node->prev;
  58   node->prev->next = node->next;
  59 }
  60
  61 static int unmarshall_long(char *data, struct queue_entry *q,
  62                            size_t offset,
  63                            void (*error_handler)(const char *, void *),
  64                            void *u) {
  65   if(xstrtol(&VALUE(q, offset, long), data, 0, 0)) {
  66     error_handler(strerror(errno), u);
  67     return -1;
  68   }
  69   return 0;
  70 }
  71
  72 static const char *marshall_long(const struct queue_entry *q, size_t offset) {
  73   char buffer[256];
  74   int n;
  75
  76   n = byte_snprintf(buffer, sizeof buffer, "%ld", VALUE(q, offset, long));
  77   if(n < 0)
  78     fatal(errno, "error converting int");
  79   else if((size_t)n >= sizeof buffer)
  80     fatal(0, "long converted to decimal is too long");
  81   return xstrdup(buffer);
  82 }
  83
  84 static int unmarshall_string(char *data, struct queue_entry *q,
  85                              size_t offset,
  86                              void attribute((unused)) (*error_handler)(const char *, void *),
  87                              void attribute((unused)) *u) {
  88   VALUE(q, offset, char *) = data;
  89   return 0;
  90 }
  91
  92 static const char *marshall_string(const struct queue_entry *q, size_t offset) {
  93   return VALUE(q, offset, char *);
  94 }
  95
  96 static int unmarshall_time_t(char *data, struct queue_entry *q,
  97                              size_t offset,
  98                              void (*error_handler)(const char *, void *),
  99                              void *u) {
 100   long_long ul;
 101
 102   if(xstrtoll(&ul, data, 0, 0)) {
 103     error_handler(strerror(errno), u);
 104     return -1;
 105   }
 106   VALUE(q, offset, time_t) = ul;
 107   return 0;
 108 }
 109
 110 static const char *marshall_time_t(const struct queue_entry *q, size_t offset) {
 111   char buffer[256];
 112   int n;
 113
 114   n = byte_snprintf(buffer, sizeof buffer,
 115                     "%"PRIdMAX, (intmax_t)VALUE(q, offset, time_t));
 116   if(n < 0)
 117     fatal(errno, "error converting time");
 118   else if((size_t)n >= sizeof buffer)
 119     fatal(0, "time converted to decimal is too long");
 120   return xstrdup(buffer);
 121 }
 122
 123 static int unmarshall_state(char *data, struct queue_entry *q,
 124                             size_t offset,
 125                             void (*error_handler)(const char *, void *),
 126                             void *u) {
 127   int n;
 128
 129   if((n = table_find(playing_states, 0, sizeof (char *),
 130                      sizeof playing_states / sizeof *playing_states,
 131                      data)) < 0) {
 132     D(("state=[%s] n=%d", data, n));
 133     error_handler("invalid state", u);
 134     return -1;
 135   }
 136   VALUE(q, offset, enum playing_state) = n;
 137   return 0;
 138 }
 139
 140 static const char *marshall_state(const struct queue_entry *q, size_t offset) {
 141   return playing_states[VALUE(q, offset, enum playing_state)];
 142 }
 143
 144 #define F(n, h) { #n, offsetof(struct queue_entry, n), marshall_##h, unmarshall_##h }
 145
 146 static const struct field {
 147   const char *name;
 148   size_t offset;
 149   const char *(*marshall)(const struct queue_entry *q, size_t offset);
 150   int (*unmarshall)(char *data, struct queue_entry *q, size_t offset,
 151                     void (*error_handler)(const char *, void *),
 152                     void *u);
 153 } fields[] = {
 154   /* Keep this table sorted. */
 155   F(expected, time_t),
 156   F(id, string),
 157   F(played, time_t),
 158   F(scratched, string),
 159   F(sofar, long),
 160   F(state, state),
 161   F(submitter, string),
 162   F(track, string),
 163   F(when, time_t),
 164   F(wstat, long)
 165 };
 166
 167 int queue_unmarshall(struct queue_entry *q, const char *s,
 168                      void (*error_handler)(const char *, void *),
 169                      void *u) {
 170   char **vec;
 171   int nvec;
 172
 173   if(!(vec = split(s, &nvec, SPLIT_QUOTES, error_handler, u)))
 174     return -1;
 175   return queue_unmarshall_vec(q, nvec, vec, error_handler, u);
 176 }
 177
 178 int queue_unmarshall_vec(struct queue_entry *q, int nvec, char **vec,
 179                          void (*error_handler)(const char *, void *),
 180                          void *u) {
 181   int n;
 182
 183   if(nvec % 2 != 0) {
 184     error_handler("invalid marshalled queue format", u);
 185     return -1;
 186   }
 187   while(*vec) {
 188     D(("key %s value %s", vec[0], vec[1]));
 189     if((n = TABLE_FIND(fields, name, *vec)) < 0) {
 190       error_handler("unknown key in queue data", u);
 191       return -1;
 192     } else {
 193       if(fields[n].unmarshall(vec[1], q, fields[n].offset, error_handler, u))
 194         return -1;
 195     }
 196     vec += 2;
 197   }
 198   return 0;
 199 }
 200
 201 char *queue_marshall(const struct queue_entry *q) {
 202   unsigned n;
 203   const char *vec[sizeof fields / sizeof *fields], *v;
 204   char *r, *s;
 205   size_t len = 1;
 206
 207   for(n = 0; n < sizeof fields / sizeof *fields; ++n)
 208     if((v = fields[n].marshall(q, fields[n].offset))) {
 209       vec[n] = quoteutf8(v);
 210       len += strlen(vec[n]) + strlen(fields[n].name) + 2;
 211     } else
 212       vec[n] = 0;
 213   s = r = xmalloc_noptr(len);
 214   for(n = 0; n < sizeof fields / sizeof *fields; ++n)
 215     if(vec[n]) {
 216       *s++ = ' ';
 217       s += strlen(strcpy(s, fields[n].name));
 218       *s++ = ' ';
 219       s += strlen(strcpy(s, vec[n]));
 220     }
 221   return r;
 222 }
 223
 224 /*
 225 Local Variables:
 226 c-basic-offset:2
 227 comment-column:40
 228 fill-column:79
 229 End:
 230 */