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// file : core/sql.c
// project : Salis-VM
// author : Paul Oliver <contact@pauloliver.dev>
// index:
// [section] includes
// [section] macros
// [section] globals
// [section] definitions
// ----------------------------------------------------------------------------
// [section] includes
// ----------------------------------------------------------------------------
#include <assert.h>
#include <sqlite3.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include "logger.h"
#include "sql.h"
// ----------------------------------------------------------------------------
// [section] macros
// ----------------------------------------------------------------------------
#define DATA_PUSH_BUSY_TIMEOUT 600000
// ----------------------------------------------------------------------------
// [section] globals
// ----------------------------------------------------------------------------
sqlite3 *g_sim_db;
// ----------------------------------------------------------------------------
// [section] definitions
// ----------------------------------------------------------------------------
void sql_open(void) {
sqlite3_open(DATA_PUSH_PATH, &g_sim_db);
assert(g_sim_db);
// Install busy handler to retry transactions if DB is locked
sqlite3_busy_timeout(g_sim_db, DATA_PUSH_BUSY_TIMEOUT);
// Enable Write-Ahead Logging (WAL)
// This seems to help prevent DB locks when displaying live data.
// See: https://sqlite.org/wal.html
sql_exec(NULL, NULL, "pragma journal_mode=wal;");
}
void sql_close(void) {
assert(g_sim_db);
sqlite3_close(g_sim_db);
}
void sql_exec(void (*callback)(sqlite3_stmt *sql_stmt, void *data), void *data, const char *sql_format, ...) {
assert(sql_format);
va_list args;
va_start(args, sql_format);
int sql_len = vsnprintf(NULL, 0, sql_format, args) + 1;
char *sql_str = malloc(sql_len);
assert(sql_str);
va_end(args);
va_start(args, sql_format);
vsprintf(sql_str, sql_format, args);
va_end(args);
int sql_res;
sqlite3_stmt *sql_stmt;
sql_res = sqlite3_prepare_v2(g_sim_db, sql_str, -1, &sql_stmt, NULL);
assert(sql_res == SQLITE_OK);
free(sql_str);
while (true) {
sql_res = sqlite3_step(sql_stmt);
if (sql_res == SQLITE_ROW) {
if (callback) {
callback(sql_stmt, data);
}
continue;
}
if (sql_res == SQLITE_DONE) {
break;
}
log_attention("SQLite database returned error %d with message:", sql_res);
log_attention(sqlite3_errmsg(g_sim_db));
// Only handle SQLITE_BUSY error, in which case we retry the query.
// Setting 'journal_mode=wal;' should help prevent busy database errors.
if (sql_res == SQLITE_BUSY) {
log_info("Will retry query");
continue;
}
assert(false);
}
sqlite3_finalize(sql_stmt);
}
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