Files
erlang-sqlite3/priv/sqlite3_drv.c
2009-10-14 17:38:14 +04:00

292 lines
7.8 KiB
C

#include "sqlite3_drv.h"
// Callback Array
static ErlDrvEntry basic_driver_entry = {
NULL, /* init */
start, /* startup (defined below) */
stop, /* shutdown (defined below) */
NULL, /* output */
NULL, /* ready_input */
NULL, /* ready_output */
"sqlite3_drv", /* the name of the driver */
NULL, /* finish */
NULL, /* handle */
NULL, /* control */
NULL, /* timeout */
outputv, /* outputv (defined below) */
ready_async, /* ready_async */
NULL, /* flush */
NULL, /* call */
NULL, /* event */
ERL_DRV_EXTENDED_MARKER, /* ERL_DRV_EXTENDED_MARKER */
ERL_DRV_EXTENDED_MAJOR_VERSION, /* ERL_DRV_EXTENDED_MAJOR_VERSION */
ERL_DRV_EXTENDED_MAJOR_VERSION, /* ERL_DRV_EXTENDED_MINOR_VERSION */
ERL_DRV_FLAG_USE_PORT_LOCKING /* ERL_DRV_FLAGs */
};
DRIVER_INIT(basic_driver) {
return &basic_driver_entry;
}
// Driver Start
static ErlDrvData start(ErlDrvPort port, char* cmd) {
sqlite3_drv_t* retval = (sqlite3_drv_t*) driver_alloc(sizeof(sqlite3_drv_t));
struct sqlite3 *db;
int status;
// Create and open the database
sqlite3_open(DB_PATH, &db);
status = sqlite3_errcode(db);
if(status != SQLITE_OK) {
fprintf(stderr, "Unabled to open file: %s because %s\n\n", DB_PATH, sqlite3_errmsg(db));
}
fprintf(stderr, "Opened file %s\n", DB_PATH);
// Set the state for the driver
retval->port = port;
retval->db = db;
return (ErlDrvData) retval;
}
// Driver Stop
static void stop(ErlDrvData handle) {
sqlite3_drv_t* driver_data = (sqlite3_drv_t*) handle;
sqlite3_close(driver_data->db);
driver_free(driver_data);
}
// Handle input from Erlang VM
static void outputv(ErlDrvData handle, ErlIOVec *ev) {
sqlite3_drv_t* driver_data = (sqlite3_drv_t*) handle;
ErlDrvBinary* data = ev->binv[1];
int command = data->orig_bytes[0];
switch(command) {
case CMD_SQL_EXEC:
sql_exec(driver_data, ev);
break;
//
// // case CMD_GET:
// // get(driver_data, ev);
// // break;
// //
// // case CMD_DEL:
// // del(driver_data, ev);
// // break;
//
default:
unkown(driver_data, ev);
}
}
static void ready_async(ErlDrvData drv_data, ErlDrvThreadData thread_data)
{
}
static int callback(void *data, int argc, char **argv, char **azColName)
{
sqlite3_drv_t *drv = (sqlite3_drv_t *)data;
int i;
// ErlDrvTermData spec[] = {ERL_DRV_ATOM, driver_mk_atom("error"),
// ERL_DRV_STRING, error_reason, strlen(error_reason),
// ERL_DRV_TUPLE, 2};
//
// driver_output_term(drv->port, spec, sizeof(spec) / sizeof(spec[0]));
// record_list = malloc(argc * sizeof(ETERM *));
fprintf(stderr, "runs %d\n", argc);
for (i = 0; i < argc; i++) {
fprintf(stderr, "%s = %s\n", azColName[i], argv[i] ? argv[i] : "NULL");
}
fprintf(stderr, "\n");
fflush(stderr);
// result = erl_cons(erl_mk_tuple(record_list, argc), result);
// free(record_list);
return 0;
}
static void sql_exec(sqlite3_drv_t *drv, ErlIOVec *ev) {
ErlDrvBinary* input = ev->binv[1];
char *command = input->orig_bytes + 1;
int command_size = input->orig_size - 1;
int status;
char *error = NULL;
fprintf(stderr, "Exec: %*s\n", command_size, command);
status = sqlite3_exec(drv->db, command, callback, drv, &error);
if(status != SQLITE_OK) {
ErlDrvTermData spec[] = {ERL_DRV_ATOM, driver_mk_atom("error"),
ERL_DRV_STRING, error, strlen(error),
ERL_DRV_TUPLE, 2};
driver_output_term(drv->port, spec, sizeof(spec) / sizeof(spec[0]));
}
if (error) {
sqlite3_free(error);
}
}
#if 0
// Retrieve a record from the database, if it exists
static void get(sqlite3_drv_t *bdb_drv, ErlIOVec *ev) {
ErlDrvBinary* input = ev->binv[1];
ErlDrvBinary *output_bytes;
char *bytes = input->orig_bytes;
char *key_bytes = bytes+1;
DB *db = bdb_drv->db;
DBT key;
DBT value;
int status;
bzero(&key, sizeof(DBT));
bzero(&value, sizeof(DBT));
key.data = key_bytes;
key.size = KEY_SIZE;
// Have BerkeleyDB allocate memory big enough to store the value
value.flags = DB_DBT_MALLOC; // Don't forget to free it later
// Retrieve the record
status = db->get(db, NULL, &key, &value, 0);
if(status == 0) {
// Get went OK
// Copy the record value to an output structure to return to Erlang VM
output_bytes = driver_alloc_binary(value.size);
output_bytes->orig_size = value.size;
memcpy(output_bytes->orig_bytes, value.data, value.size);
free(value.data);
// TODO:Figure out if we can somehow use this original memory without recopying a la:
//binary->orig_bytes = (char *)&data.data;
// Returns tuple {ok, Data}
ErlDrvTermData spec[] = {ERL_DRV_ATOM, driver_mk_atom("ok"),
ERL_DRV_BINARY, (ErlDrvTermData) output_bytes, output_bytes->orig_size, 0,
ERL_DRV_TUPLE, 2};
driver_output_term(bdb_drv->port, spec, sizeof(spec) / sizeof(spec[0]));
driver_free_binary(output_bytes);
} else {
// there was an error
char *error_reason;
switch(status) {
case DB_LOCK_DEADLOCK:
error_reason = "deadlock";
break;
case DB_SECONDARY_BAD:
error_reason = "bad_secondary_index";
break;
case ENOMEM:
error_reason = "insufficient_memory";
break;
case EINVAL:
error_reason = "bad_flag";
break;
case DB_RUNRECOVERY:
error_reason = "run_recovery";
break;
default:
error_reason = "unknown";
}
// Return tuple {error, Reason}
ErlDrvTermData spec[] = {ERL_DRV_ATOM, driver_mk_atom("error"),
ERL_DRV_ATOM, driver_mk_atom(error_reason),
ERL_DRV_TUPLE, 2};
driver_output_term(bdb_drv->port, spec, sizeof(spec) / sizeof(spec[0]));
}
}
// Delete a record from the database
static void del(sqlite3_drv_t *bdb_drv, ErlIOVec *ev) {
ErlDrvBinary* data = ev->binv[1];
char *bytes = data->orig_bytes;
char *key_bytes = bytes+1;
DB *db = bdb_drv->db;
DBT key;
int status;
bzero(&key, sizeof(DBT));
key.data = key_bytes;
key.size = KEY_SIZE;
status = db->del(db, NULL, &key, 0);
db->sync(db, 0);
if(status == 0) {
// Delete went OK, return atom 'ok'
ErlDrvTermData spec[] = {ERL_DRV_ATOM, driver_mk_atom("ok")};
driver_output_term(bdb_drv->port, spec, sizeof(spec) / sizeof(spec[0]));
} else {
// There was an error
char *error_reason;
switch(status) {
case DB_NOTFOUND:
error_reason = "not_found";
break;
case DB_LOCK_DEADLOCK:
error_reason = "deadlock";
break;
case DB_SECONDARY_BAD:
error_reason = "bad_secondary_index";
break;
case EINVAL:
error_reason = "bad_flag";
break;
case EACCES:
error_reason = "readonly";
break;
case DB_RUNRECOVERY:
error_reason = "run_recovery";
break;
default:
error_reason = "unknown";
}
// Return tuple {error, Reason}
ErlDrvTermData spec[] = {ERL_DRV_ATOM, driver_mk_atom("error"),
ERL_DRV_ATOM, driver_mk_atom(error_reason),
ERL_DRV_TUPLE, 2};
driver_output_term(bdb_drv->port, spec, sizeof(spec) / sizeof(spec[0]));
}
}
#endif
// Unkown Command
static void unkown(sqlite3_drv_t *bdb_drv, ErlIOVec *ev) {
// Return {error, unkown_command}
ErlDrvTermData spec[] = {ERL_DRV_ATOM, driver_mk_atom("error"),
ERL_DRV_ATOM, driver_mk_atom("uknown_command"),
ERL_DRV_TUPLE, 2};
driver_output_term(bdb_drv->port, spec, sizeof(spec) / sizeof(spec[0]));
}