src/mapdb.c

   1 #include <stdio.h>
   2 #include <endian.h>
   3 #include <stdlib.h>
   4 #include "mapdb.h"
   5 #include "servermap.h"
   6
   7 static void print_error(sqlite3 *db, MapBlock *block, const char *action)
   8 {
   9         printf("Database error with %s block at %d %d %d: %s\n", action, block->pos.x, block->pos.y, block->pos.z, sqlite3_errmsg(db));
  10 }
  11
  12 sqlite3 *open_mapdb(const char *path)
  13 {
  14         sqlite3 *db;
  15         char *err;
  16
  17         if (sqlite3_open_v2(path, &db, SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | SQLITE_OPEN_FULLMUTEX, NULL) != SQLITE_OK) {
  18                 printf("Failed to open database: %s\n", sqlite3_errmsg(db));
  19         } else if (sqlite3_exec(db, "CREATE TABLE IF NOT EXISTS blocks (pos BLOB PRIMARY KEY, data BLOB NOT NULL);", NULL, NULL, &err) != SQLITE_OK) {
  20                 printf("Failed to initialize database: %s\n", err);
  21                 sqlite3_free(err);
  22         }
  23
  24         return db;
  25 }
  26
  27 static sqlite3_stmt *prepare_statement(sqlite3 *db, MapBlock *block, const char *action, const char *sql)
  28 {
  29         sqlite3_stmt *stmt;
  30
  31         if (sqlite3_prepare_v2(db, sql, -1, &stmt, NULL) != SQLITE_OK) {
  32                 print_error(db, block, action);
  33                 return NULL;
  34         }
  35
  36         size_t psize = sizeof(s32) * 3;
  37         s32 *pos = malloc(psize);
  38         pos[0] = htobe32(block->pos.x);
  39         pos[1] = htobe32(block->pos.y);
  40         pos[2] = htobe32(block->pos.z);
  41
  42         sqlite3_bind_blob(stmt, 1, pos, psize, &free);
  43
  44         return stmt;
  45 }
  46
  47 bool load_block(sqlite3 *db, MapBlock *block)
  48 {
  49         sqlite3_stmt *stmt;
  50
  51         if (! (stmt = prepare_statement(db, block, "loading", "SELECT data FROM blocks WHERE pos=?")))
  52                 return false;
  53
  54         int rc = sqlite3_step(stmt);
  55         bool found = rc == SQLITE_ROW;
  56
  57         if (found) {
  58                 const char *data = sqlite3_column_blob(stmt, 0);
  59                 map_deserialize_block(block, data + sizeof(MapBlockHeader), be64toh(*(MapBlockHeader *) data));
  60         } else if (rc != SQLITE_DONE) {
  61                 print_error(db, block, "loading");
  62         }
  63
  64         sqlite3_finalize(stmt);
  65         return found;
  66 }
  67
  68 void save_block(sqlite3 *db, MapBlock *block)
  69 {
  70         sqlite3_stmt *stmt;
  71
  72         if (! (stmt = prepare_statement(db, block, "saving", "REPLACE INTO blocks (pos, data) VALUES(?1, ?2)")))
  73                 return;
  74
  75         MapBlockExtraData *extra = block->extra;
  76
  77         sqlite3_bind_blob(stmt, 2, extra->data, extra->size, SQLITE_TRANSIENT);
  78
  79         if (sqlite3_step(stmt) != SQLITE_DONE)
  80                 print_error(db, block, "saving");
  81
  82         sqlite3_finalize(stmt);
  83 }