我想知道这段代码发生了什么，取自 LuaSQL 代码（它位于 LuaSQL 源代码 - 文件 ls_OCI8.c）。
我想了解这段代码的作用（更具体地说：我想了解 ASSERT 函数在做什么）。据我所知，assert标准函数是：void assert(int expression)。它没有三个参数。
ASSERT (L, OCIParamGet (cur->stmthp, OCI_HTYPE_STMT, cur->errhp,
(dvoid **)¶m, i), cur->errhp);
ASSERT (L, OCIAttrGet (param, OCI_DTYPE_PARAM,
(dvoid *)&(name), (ub4 *)&(col->namelen),
OCI_ATTR_NAME, cur->errhp), cur->errhp);
copy_column_name (col, name);
ASSERT (L, OCIAttrGet (param, OCI_DTYPE_PARAM,
(dvoid *)&(col->type), (ub4 *)0, OCI_ATTR_DATA_TYPE,
cur->errhp), cur->errhp);
整个源代码是：
/*
** LuaSQL, Oracle driver
** Authors: Tomas Guisasola, Leonardo Godinho
** See Copyright Notice in license.html
** $Id: ls_oci8.c,v 1.31 2009/02/07 23:16:23 tomas Exp $
*/
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "oci.h"
#include "oratypes.h"
#include "ociapr.h"
#include "ocidem.h"
#include "lua.h"
#include "lauxlib.h"
#include "luasql.h"
#define LUASQL_ENVIRONMENT_OCI8 "Oracle environment"
#define LUASQL_CONNECTION_OCI8 "Oracle connection"
#define LUASQL_CURSOR_OCI8 "Oracle cursor"
typedef struct {
short closed;
int conn_counter;
OCIEnv *envhp;
OCIError *errhp; /* !!! */
} env_data;
typedef struct {
short closed;
short loggedon;
short auto_commit; /* 0 for manual commit */
int cur_counter;
int env; /* reference to environment */
OCISvcCtx *svchp; /* service handle */
OCIError *errhp; /* !!! */
} conn_data;
typedef union {
int i;
char *s;
double d;
} column_value;
typedef struct {
ub2 type; /* database type */
text *name; /* column name */
ub4 namelen; /* column name length */
ub2 max; /* maximum size */
sb2 null; /* is null? */
OCIDefine *define; /* define handle */
column_value val;
} column_data;
typedef struct {
short closed;
int conn; /* reference to connection */
int numcols; /* number of columns */
int colnames, coltypes; /* reference to column info tables */
int curr_tuple; /* next tuple to be read */
char *text; /* text of SQL statement */
OCIStmt *stmthp; /* statement handle */
OCIError *errhp; /* !!! */
column_data *cols; /* array of columns */
} cur_data;
int checkerr (lua_State *L, sword status, OCIError *errhp);
#define ASSERT(L,exp,err) {sword s = exp; if (s) return checkerr (L, s, err);}
LUASQL_API int luaopen_luasql_oci8 (lua_State *L);
/*
** Check for valid environment.
*/
static env_data *getenvironment (lua_State *L) {
env_data *env = (env_data *)luaL_checkudata (L, 1, LUASQL_ENVIRONMENT_OCI8);
luaL_argcheck (L, env != NULL, 1, LUASQL_PREFIX"environment expected");
luaL_argcheck (L, !env->closed, 1, LUASQL_PREFIX"environment is closed");
return env;
}
/*
** Check for valid connection.
*/
static conn_data *getconnection (lua_State *L) {
conn_data *conn = (conn_data *)luaL_checkudata (L, 1, LUASQL_CONNECTION_OCI8);
luaL_argcheck (L, conn != NULL, 1, LUASQL_PREFIX"connection expected");
luaL_argcheck (L, !conn->closed, 1, LUASQL_PREFIX"connection is closed");
return conn;
}
/*
** Check for valid cursor.
*/
static cur_data *getcursor (lua_State *L) {
cur_data *cur = (cur_data *)luaL_checkudata (L, 1, LUASQL_CURSOR_OCI8);
luaL_argcheck (L, cur != NULL, 1, LUASQL_PREFIX"cursor expected");
luaL_argcheck (L, !cur->closed, 1, LUASQL_PREFIX"cursor is closed");
return cur;
}
/*
** Push nil plus an error message.
*/
int checkerr (lua_State *L, sword status, OCIError *errhp) {
lua_pushnil (L);
switch (status) {
case OCI_SUCCESS:
lua_pushnil (L); /* !!!!!!!!!!!!! */
break;
case OCI_SUCCESS_WITH_INFO:
lua_pushstring (L, LUASQL_PREFIX"Success with info!");
break;
case OCI_NEED_DATA:
lua_pushstring (L, LUASQL_PREFIX"OCI_NEED_DATA");
break;
case OCI_NO_DATA:
lua_pushstring (L, LUASQL_PREFIX"OCI_NODATA");
break;
case OCI_ERROR: {
text errbuf[512];
sb4 errcode = 0;
OCIErrorGet (errhp, (ub4) 1, (text *) NULL, &errcode,
errbuf, (ub4) sizeof (errbuf), OCI_HTYPE_ERROR);
lua_pushstring (L, LUASQL_PREFIX);
lua_pushstring (L, errbuf);
lua_concat (L, 2);
break;
}
case OCI_INVALID_HANDLE:
lua_pushstring (L, LUASQL_PREFIX"OCI_INVALID_HANDLE");
break;
case OCI_STILL_EXECUTING:
lua_pushstring (L, LUASQL_PREFIX"OCI_STILL_EXECUTE");
break;
case OCI_CONTINUE:
lua_pushstring (L, LUASQL_PREFIX"OCI_CONTINUE");
break;
}
return 2;
}
/*
** Copy the column name to the column structure and convert it to lower case.
*/
static void copy_column_name (column_data *col, text *name) {
unsigned int i;
col->name = (text *)malloc (col->namelen);
memcpy (col->name, name, col->namelen);
for (i = 0; i < col->namelen; i++)
col->name[i] = tolower (col->name[i]);
}
/*
** Alloc buffers for column values.
*/
static int alloc_column_buffer (lua_State *L, cur_data *cur, int i) {
/* column index ranges from 1 to numcols */
/* C array index ranges from 0 to numcols-1 */
column_data *col = &(cur->cols[i-1]);
OCIParam *param;
text *name;
ASSERT (L, OCIParamGet (cur->stmthp, OCI_HTYPE_STMT, cur->errhp,
(dvoid **)¶m, i), cur->errhp);
ASSERT (L, OCIAttrGet (param, OCI_DTYPE_PARAM,
(dvoid *)&(name), (ub4 *)&(col->namelen),
OCI_ATTR_NAME, cur->errhp), cur->errhp);
copy_column_name (col, name);
ASSERT (L, OCIAttrGet (param, OCI_DTYPE_PARAM,
(dvoid *)&(col->type), (ub4 *)0, OCI_ATTR_DATA_TYPE,
cur->errhp), cur->errhp);
switch (col->type) {
case SQLT_CHR:
case SQLT_STR:
case SQLT_VCS:
case SQLT_AFC:
case SQLT_AVC:
ASSERT (L, OCIAttrGet (param, OCI_DTYPE_PARAM,
(dvoid *)&(col->max), 0, OCI_ATTR_DATA_SIZE,
cur->errhp), cur->errhp);
col->val.s = calloc (col->max + 1, sizeof(col->val.s));
ASSERT (L, OCIDefineByPos (cur->stmthp, &(col->define),
cur->errhp, (ub4)i, col->val.s, col->max+1,
SQLT_STR /*col->type*/, (dvoid *)&(col->null), (ub2 *)0,
(ub2 *)0, (ub4) OCI_DEFAULT), cur->errhp);
break;
case SQLT_NUM:
case SQLT_FLT:
case SQLT_INT:
/* case SQLT_UIN: */
ASSERT (L, OCIDefineByPos (cur->stmthp, &(col->define),
cur->errhp, (ub4)i, &(col->val.d), sizeof(col->val.d),
SQLT_FLT, (dvoid *)&(col->null), (ub2 *)0,
(ub2 *)0, (ub4) OCI_DEFAULT), cur->errhp);
break;
case SQLT_CLOB: {
env_data *env;
conn_data *conn;
lua_rawgeti (L, LUA_REGISTRYINDEX, cur->conn);
conn = (conn_data *)lua_touserdata (L, -1);
lua_rawgeti (L, LUA_REGISTRYINDEX, conn->env);
env = (env_data *)lua_touserdata (L, -1);
lua_pop (L, 2);
ASSERT (L, OCIDescriptorAlloc (env->envhp, (dvoid *)&(col->val.s),
OCI_DTYPE_LOB, (size_t)0, (dvoid **)0), cur->errhp);
ASSERT (L, OCIDefineByPos (cur->stmthp, &(col->define),
cur->errhp, (ub4)i, &(col->val.s), (sb4)sizeof(dvoid *),
SQLT_CLOB, (dvoid *)&(col->null), (ub2 *)0, (ub2 *)0,
OCI_DEFAULT), cur->errhp);
break;
}
default:
luaL_error (L, LUASQL_PREFIX"invalid type %d #%d", col->type, i);
break;
}
return 0;
}
/*
** Deallocate column buffers.
*/
static int free_column_buffers (lua_State *L, cur_data *cur, int i) {
/* column index ranges from 1 to numcols */
/* C array index ranges from 0 to numcols-1 */
column_data *col = &(cur->cols[i-1]);
free (col->name);
switch (col->type) {
case SQLT_INT:
case SQLT_FLT:
case SQLT_NUM:
break;
case SQLT_CHR:
case SQLT_STR:
case SQLT_VCS:
case SQLT_AFC:
case SQLT_AVC:
free(col->val.s);
break;
case SQLT_CLOB:
ASSERT (L, OCIDescriptorFree (col->val.s,
OCI_DTYPE_LOB), cur->errhp);
break;
default:
luaL_error (L, LUASQL_PREFIX"unknown type");
/*printf("free_buffers(): Unknow Type: %d count: %d\n",cols.item[count].type, count );*/
break;
}
return 0;
}
/*
** Push a value on top of the stack.
*/
static int pushvalue (lua_State *L, cur_data *cur, int i) {
/* column index ranges from 1 to numcols */
/* C array index ranges from 0 to numcols-1 */
column_data *col = &(cur->cols[i-1]);
if (col->null) {
/* Oracle NULL => Lua nil */
lua_pushnil (L);
return 1;
}
switch (col->type) {
case SQLT_NUM:
case SQLT_INT:
case SQLT_FLT:
lua_pushnumber (L, col->val.d);
break;
case SQLT_CHR:
case SQLT_STR:
case SQLT_VCS:
case SQLT_AFC:
case SQLT_AVC:
lua_pushstring (L, (char *)(col->val.s));
break;
case SQLT_CLOB: {
ub4 lob_len;
conn_data *conn;
env_data *env;
lua_rawgeti (L, LUA_REGISTRYINDEX, cur->conn);
conn = lua_touserdata (L, -1);
lua_rawgeti (L, LUA_REGISTRYINDEX, conn->env);
env = lua_touserdata (L, -1);
lua_pop (L, 2);
ASSERT (L, OCILobGetLength (conn->svchp, cur->errhp,
(OCILobLocator *)col->val.s, &lob_len), cur->errhp);
if (lob_len > 0) {
char *lob_buffer=malloc(lob_len);
ub4 amount = lob_len;
ASSERT(L, OCILobRead(conn->svchp, cur->errhp,
(OCILobLocator *) col->val.s, &amount, (ub4) 1,
(dvoid *) lob_buffer, (ub4) lob_len, (dvoid *)0,
(sb4 (*) (dvoid *, CONST dvoid *, ub4, ub1)) 0,
(ub2) 0, (ub1) SQLCS_IMPLICIT), cur->errhp);
lua_pushlstring (L, lob_buffer, amount);
free(lob_buffer);
} else {
lua_pushstring (L, "");
}
break;
}
default:
luaL_error (L, LUASQL_PREFIX"unexpected error");
}
return 1;
}
/*
** Get another row of the given cursor.
*/
static int cur_fetch (lua_State *L) {
cur_data *cur = getcursor (L);
sword status = OCIStmtFetch (cur->stmthp, cur->errhp, 1,
OCI_FETCH_NEXT, OCI_DEFAULT);
if (status == OCI_NO_DATA) {
/* No more rows */
lua_pushnil (L);
return 1;
} else if (status != OCI_SUCCESS) {
/* Error */
return checkerr (L, status, cur->errhp);
}
if (lua_istable (L, 2)) {
int i;
const char *opts = luaL_optstring (L, 3, "n");
if (strchr (opts, 'n') != NULL)
/* Copy values to numerical indices */
for (i = 1; i <= cur->numcols; i++) {
int ret = pushvalue (L, cur, i);
if (ret != 1)
return ret;
lua_rawseti (L, 2, i);
}
if (strchr (opts, 'a') != NULL)
/* Copy values to alphanumerical indices */
for (i = 1; i <= cur->numcols; i++) {
column_data *col = &(cur->cols[i-1]);
int ret;
lua_pushlstring (L, col->name, col->namelen);
if ((ret = pushvalue (L, cur, i)) != 1)
return ret;
lua_rawset (L, 2);
}
lua_pushvalue(L, 2);
return 1; /* return table */
}
else {
int i;
luaL_checkstack (L, cur->numcols, LUASQL_PREFIX"too many columns");
for (i = 1; i <= cur->numcols; i++) {
int ret = pushvalue (L, cur, i);
if (ret != 1)
return ret;
}
return cur->numcols; /* return #numcols values */
}
}
/*
** Close the cursor on top of the stack.
** Return 1
*/
static int cur_close (lua_State *L) {
int i;
conn_data *conn;
cur_data *cur = (cur_data *)luaL_checkudata (L, 1, LUASQL_CURSOR_OCI8);
luaL_argcheck (L, cur != NULL, 1, LUASQL_PREFIX"cursor expected");
if (cur->closed) {
lua_pushboolean (L, 0);
return 1;
}
/* Deallocate buffers. */
for (i = 1; i <= cur->numcols; i++) {
int ret = free_column_buffers (L, cur, i);
if (ret)
return ret;
}
free (cur->cols);
free (cur->text);
/* Nullify structure fields. */
cur->closed = 1;
if (cur->stmthp)
OCIHandleFree ((dvoid *)cur->stmthp, OCI_HTYPE_STMT);
if (cur->errhp)
OCIHandleFree ((dvoid *)cur->errhp, OCI_HTYPE_ERROR);
/* Decrement cursor counter on connection object */
lua_rawgeti (L, LUA_REGISTRYINDEX, cur->conn);
conn = lua_touserdata (L, -1);
conn->cur_counter--;
luaL_unref (L, LUA_REGISTRYINDEX, cur->conn);
luaL_unref (L, LUA_REGISTRYINDEX, cur->colnames);
luaL_unref (L, LUA_REGISTRYINDEX, cur->coltypes);
lua_pushboolean (L, 1);
return 1;
}
/*
** Return the list of field names as a table on top of the stack.
*/
static int cur_getcolnames (lua_State *L) {
cur_data *cur = getcursor (L);
if (cur->colnames != LUA_NOREF)
lua_rawgeti (L, LUA_REGISTRYINDEX, cur->colnames);
else {
int i;
lua_newtable (L);
for (i = 1; i <= cur->numcols; i++) {
column_data *col = &(cur->cols[i-1]);
lua_pushlstring (L, col->name, col->namelen);
lua_rawseti (L, -2, i);
}
lua_pushvalue (L, -1);
cur->colnames = luaL_ref (L, LUA_REGISTRYINDEX);
}
return 1;
}
/*
**
*/
static char *getcolumntype (column_data *col) {
switch (col->type) {
case SQLT_CHR:
case SQLT_STR:
case SQLT_VCS:
case SQLT_AFC:
case SQLT_AVC:
return "string";
case SQLT_NUM:
case SQLT_FLT:
case SQLT_INT:
/* case SQLT_UIN: */
return "number";
case SQLT_CLOB:
return "string";
default:
return "";
}
}
/*
** Return the list of field types as a table on top of the stack.
*/
static int cur_getcoltypes (lua_State *L) {
cur_data *cur = getcursor (L);
if (cur->coltypes != LUA_NOREF)
lua_rawgeti (L, LUA_REGISTRYINDEX, cur->coltypes);
else {
int i;
lua_newtable (L);
for (i = 1; i <= cur->numcols; i++) {
column_data *col = &(cur->cols[i-1]);
lua_pushnumber (L, i);
lua_pushstring (L, getcolumntype (col));
lua_rawset (L, -3);
}
lua_pushvalue (L, -1);
cur->coltypes = luaL_ref (L, LUA_REGISTRYINDEX);
}
return 1;
}
/*
** Push the number of rows.
*/
static int cur_numrows (lua_State *L) {
int n;
cur_data *cur = getcursor (L);
ASSERT (L, OCIAttrGet ((dvoid *) cur->stmthp, OCI_HTYPE_STMT, (dvoid *)&n,
(ub4)0, OCI_ATTR_NUM_ROWS, cur->errhp), cur->errhp);
lua_pushnumber (L, n);
return 1;
}
/*
** Close a Connection object.
*/
static int conn_close (lua_State *L) {
env_data *env;
conn_data *conn = (conn_data *)luaL_checkudata (L, 1, LUASQL_CONNECTION_OCI8);
luaL_argcheck (L, conn != NULL, 1, LUASQL_PREFIX"connection expected");
if (conn->closed) {
lua_pushboolean (L, 0);
return 1;
}
if (conn->cur_counter > 0)
return luaL_error (L, LUASQL_PREFIX"there are open cursors");
/* Nullify structure fields. */
conn->closed = 1;
if (conn->svchp) {
if (conn->loggedon)
OCILogoff (conn->svchp, conn->errhp);
else
OCIHandleFree ((dvoid *)conn->svchp, OCI_HTYPE_SVCCTX);
}
if (conn->errhp)
OCIHandleFree ((dvoid *)conn->errhp, OCI_HTYPE_ERROR);
/* Decrement connection counter on environment object */
lua_rawgeti (L, LUA_REGISTRYINDEX, conn->env);
env = lua_touserdata (L, -1);
env->conn_counter--;
luaL_unref (L, LUA_REGISTRYINDEX, conn->env);
lua_pushboolean (L, 1);
return 1;
}
/*
** Create a new Cursor object and push it on top of the stack.
*/
static int create_cursor (lua_State *L, int o, conn_data *conn, OCIStmt *stmt, const char *text) {
int i;
env_data *env;
cur_data *cur = (cur_data *)lua_newuserdata(L, sizeof(cur_data));
luasql_setmeta (L, LUASQL_CURSOR_OCI8);
conn->cur_counter++;
/* fill in structure */
cur->closed = 0;
cur->numcols = 0;
cur->colnames = LUA_NOREF;
cur->coltypes = LUA_NOREF;
cur->curr_tuple = 0;
cur->stmthp = stmt;
cur->errhp = NULL;
cur->cols = NULL;
cur->text = strdup (text);
lua_pushvalue (L, o);
cur->conn = luaL_ref (L, LUA_REGISTRYINDEX);
/* error handler */
lua_rawgeti (L, LUA_REGISTRYINDEX, conn->env);
env = lua_touserdata (L, -1);
lua_pop (L, 1);
ASSERT (L, OCIHandleAlloc((dvoid *) env->envhp,
(dvoid **) &(cur->errhp), (ub4) OCI_HTYPE_ERROR, (size_t) 0,
(dvoid **) 0), conn->errhp);
/* get number of columns */
ASSERT (L, OCIAttrGet ((dvoid *)stmt, (ub4)OCI_HTYPE_STMT,
(dvoid *)&cur->numcols, (ub4 *)0, (ub4)OCI_ATTR_PARAM_COUNT,
cur->errhp), cur->errhp);
cur->cols = (column_data *)malloc (sizeof(column_data) * cur->numcols);
/* define output variables */
/* Oracle and Lua column indices ranges from 1 to numcols */
/* C array indices ranges from 0 to numcols-1 */
for (i = 1; i <= cur->numcols; i++) {
int ret = alloc_column_buffer (L, cur, i);
if (ret)
return ret;
}
return 1;
}
/*
** Execute an SQL statement.
** Return a Cursor object if the statement is a query, otherwise
** return the number of tuples affected by the statement.
*/
static int conn_execute (lua_State *L) {
env_data *env;
conn_data *conn = getconnection (L);
const char *statement = luaL_checkstring (L, 2);
sword status;
ub4 prefetch = 0;
ub4 iters;
ub4 mode;
ub2 type;
OCIStmt *stmthp;
/* get environment */
lua_rawgeti (L, LUA_REGISTRYINDEX, conn->env);
if (!lua_isuserdata (L, -1))
luaL_error(L,LUASQL_PREFIX"invalid environment in connection!");
env = (env_data *)lua_touserdata (L, -1);
/* statement handle */
ASSERT (L, OCIHandleAlloc ((dvoid *)env->envhp, (dvoid **)&stmthp,
OCI_HTYPE_STMT, (size_t)0, (dvoid **)0), conn->errhp);
ASSERT (L, OCIAttrSet ((dvoid *)stmthp, (ub4)OCI_HTYPE_STMT,
(dvoid *)&prefetch, (ub4)0, (ub4)OCI_ATTR_PREFETCH_ROWS,
conn->errhp), conn->errhp);
ASSERT (L, OCIStmtPrepare (stmthp, conn->errhp, (text *)statement,
(ub4) strlen(statement), (ub4) OCI_NTV_SYNTAX, (ub4) OCI_DEFAULT),
conn->errhp);
/* statement type */
ASSERT (L, OCIAttrGet ((dvoid *)stmthp, (ub4) OCI_HTYPE_STMT,
(dvoid *)&type, (ub4 *)0, (ub4)OCI_ATTR_STMT_TYPE, conn->errhp),
conn->errhp);
if (type == OCI_STMT_SELECT)
iters = 0;
else
iters = 1;
if (conn->auto_commit)
mode = OCI_COMMIT_ON_SUCCESS;
else
mode = OCI_DEFAULT;
/* execute statement */
status = OCIStmtExecute (conn->svchp, stmthp, conn->errhp, iters,
(ub4)0, (CONST OCISnapshot *)NULL, (OCISnapshot *)NULL, mode);
if (status && (status != OCI_NO_DATA)) {
OCIHandleFree ((dvoid *)stmthp, OCI_HTYPE_STMT);
return checkerr (L, status, conn->errhp);
}
if (type == OCI_STMT_SELECT) {
/* create cursor */
return create_cursor (L, 1, conn, stmthp, statement);
} else {
/* return number of rows */
int rows_affected;
ASSERT (L, OCIAttrGet ((dvoid *)stmthp, (ub4)OCI_HTYPE_STMT,
(dvoid *)&rows_affected, (ub4 *)0,
(ub4)OCI_ATTR_ROW_COUNT, conn->errhp), conn->errhp);
OCIHandleFree ((dvoid *)stmthp, OCI_HTYPE_STMT);
lua_pushnumber (L, rows_affected);
return 1;
}
}
/*
** Commit the current transaction.
*/
static int conn_commit (lua_State *L) {
conn_data *conn = getconnection (L);
ASSERT (L, OCITransCommit (conn->svchp, conn->errhp, OCI_DEFAULT),
conn->errhp);
/*
if (conn->auto_commit == 0)
ASSERT (L, OCITransStart (conn->svchp, conn->errhp...
*/
return 0;
}
/*
** Rollback the current transaction.
*/
static int conn_rollback (lua_State *L) {
conn_data *conn = getconnection (L);
ASSERT (L, OCITransRollback (conn->svchp, conn->errhp, OCI_DEFAULT),
conn->errhp);
/*
if (conn->auto_commit == 0)
sql_begin(conn);
*/
return 0;
}
/*
** Set "auto commit" property of the connection.
** If 'true', then rollback current transaction.
** If 'false', then start a new transaction.
*/
static int conn_setautocommit (lua_State *L) {
conn_data *conn = getconnection (L);
if (lua_toboolean (L, 2)) {
conn->auto_commit = 1;
/* Undo active transaction. */
ASSERT (L, OCITransRollback (conn->svchp, conn->errhp,
OCI_DEFAULT), conn->errhp);
}
else {
conn->auto_commit = 0;
/* sql_begin(conn);*/
}
lua_pushboolean(L, 1);
return 1;
}
/*
** Connects to a data source.
*/
static int env_connect (lua_State *L) {
env_data *env = getenvironment (L);
const char *sourcename = luaL_checkstring(L, 2);
const char *username = luaL_optstring(L, 3, NULL);
const char *password = luaL_optstring(L, 4, NULL);
/* Sizes of strings */
size_t snlen = strlen(sourcename);
size_t userlen = (username) ? strlen(username) : 0;
size_t passlen = (password) ? strlen(password) : 0;
/* Alloc connection object */
conn_data *conn = (conn_data *)lua_newuserdata(L, sizeof(conn_data));
/* fill in structure */
luasql_setmeta (L, LUASQL_CONNECTION_OCI8);
conn->env = LUA_NOREF;
conn->closed = 1;
conn->auto_commit = 1;
conn->cur_counter = 0;
conn->loggedon = 0;
conn->svchp = NULL;
conn->errhp = NULL;
lua_pushvalue (L, 1);
conn->env = luaL_ref (L, LUA_REGISTRYINDEX);
/* error handler */
ASSERT (L, OCIHandleAlloc((dvoid *) env->envhp,
(dvoid **) &(conn->errhp), /* !!! */
(ub4) OCI_HTYPE_ERROR, (size_t) 0, (dvoid **) 0), env->errhp);
/* service handler */
/*ASSERT (L, OCIHandleAlloc((dvoid *) env->envhp,
(dvoid **) &(conn->svchp),
(ub4) OCI_HTYPE_SVCCTX, (size_t) 0, (dvoid **) 0), conn->errhp);
*/
/* login */
ASSERT (L, OCILogon(env->envhp, conn->errhp, &(conn->svchp),
(CONST text*)username, userlen,
(CONST text*)password, passlen,
(CONST text*)sourcename, snlen), conn->errhp);
conn->closed = 0;
env->conn_counter++;
conn->loggedon = 1;
return 1;
}
/*
** Close environment object.
*/
static int env_close (lua_State *L) {
env_data *env = (env_data *)luaL_checkudata (L, 1, LUASQL_ENVIRONMENT_OCI8);
luaL_argcheck (L, env != NULL, 1, LUASQL_PREFIX"environment expected");
if (env->closed) {
lua_pushboolean (L, 0);
return 1;
}
if (env->conn_counter > 0)
return luaL_error (L, LUASQL_PREFIX"there are open connections");
env->closed = 1;
/* desalocar: env->errhp e env->envhp */
if (env->envhp)
OCIHandleFree ((dvoid *)env->envhp, OCI_HTYPE_ENV);
if (env->errhp)
OCIHandleFree ((dvoid *)env->errhp, OCI_HTYPE_ERROR);
lua_pushboolean (L, 1);
return 1;
}
/*
** Creates an Environment and returns it.
*/
static int create_environment (lua_State *L) {
env_data *env = (env_data *)lua_newuserdata(L, sizeof(env_data));
luasql_setmeta (L, LUASQL_ENVIRONMENT_OCI8);
/* fill in structure */
env->closed = 0;
env->conn_counter = 0;
env->envhp = NULL;
env->errhp = NULL;
/* maybe OCI_SHARED and OCI_THREADED ??? */
if (OCIEnvCreate ( &(env->envhp), (ub4)OCI_DEFAULT, (dvoid *)0,
(dvoid * (*)(dvoid *, size_t)) 0,
(dvoid * (*)(dvoid *, dvoid *, size_t)) 0,
(void (*)(dvoid *, dvoid *)) 0,
(size_t) 0,
(dvoid **) 0))
luasql_faildirect (L, "couldn't create environment");
/* error handler */
ASSERT (L, OCIHandleAlloc((dvoid *) env->envhp,
(dvoid **) &(env->errhp), /* !!! */
(ub4) OCI_HTYPE_ERROR, (size_t) 0, (dvoid **) 0), env->errhp);
return 1;
}
/*
** Create metatables for each class of object.
*/
static void create_metatables (lua_State *L) {
struct luaL_Reg environment_methods[] = {
{"__gc", env_close}, /* Should this method be changed? */
{"close", env_close},
{"connect", env_connect},
{NULL, NULL},
};
struct luaL_Reg connection_methods[] = {
{"__gc", conn_close}, /* Should this method be changed? */
{"close", conn_close},
{"execute", conn_execute},
{"commit", conn_commit},
{"rollback", conn_rollback},
{"setautocommit", conn_setautocommit},
{NULL, NULL},
};
struct luaL_Reg cursor_methods[] = {
{"__gc", cur_close}, /* Should this method be changed? */
{"close", cur_close},
{"getcolnames", cur_getcolnames},
{"getcoltypes", cur_getcoltypes},
{"fetch", cur_fetch},
{"numrows", cur_numrows},
{NULL, NULL},
};
luasql_createmeta (L, LUASQL_ENVIRONMENT_OCI8, environment_methods);
luasql_createmeta (L, LUASQL_CONNECTION_OCI8, connection_methods);
luasql_createmeta (L, LUASQL_CURSOR_OCI8, cursor_methods);
lua_pop (L, 3);
}
/*
** Creates the metatables for the objects and registers the
** driver open method.
*/
LUASQL_API int luaopen_luasql_oci8 (lua_State *L) {
struct luaL_Reg driver[] = {
{"oci8", create_environment},
{NULL, NULL},
};
create_metatables (L);
lua_newtable (L);
luaL_setfuncs (L, driver, 0);
luasql_set_info (L);
return 1;
}
提前致谢！