emfdb.c

嵌入式Linux系统用的web server,开源代码,非常好用

/*
 * emfdb.c -- EMF database compatability functions for GoAhead WebServer.
 *
 * Copyright (c) GoAhead Software Inc., 1995-2000. All Rights Reserved.
 *
 * See the file "license.txt" for usage and redistribution license requirements
 *
 * $Id: emfdb.c,v 1.4 2003/09/29 19:48:08 bporter Exp $
 */

/******************************** Description *********************************/
/*
 *	Textfile-based database support for WebServer 2.1.
 */

/********************************* Includes ***********************************/

#include	"emfdb.h"
#include	"wsIntrn.h"

/********************************* Defines ************************************/

#define KEYWORD_TABLE	T("TABLE")
#define KEYWORD_ROW		T("ROW")

/*********************************** Locals ***********************************/

/*
 *	Variable to support the basicSet and basicGet functions.
 */

static char_t	*basicProdDir = NULL;		
static char_t	*basicDefaultDir = T("."); /* Default set to current */

/*
 * hAlloc chain list of table schemas to be closed 
 */

static int			dbMaxTables = 0;
static dbTable_t	**dbListTables = NULL;

/****************************** Forward Declarations **************************/

static int		crack(char_t *buf, char_t **key, char_t **val);
static char_t	*trim(char_t *str);
static int		GetColumnIndex(int tid, char_t *colName);

/******************************************************************************/
/* 
 *	Add a schema to the module-internal schema database 
 */

int dbRegisterDBSchema(dbTable_t *pTableRegister)
{
	dbTable_t	*pTable;
	int			tid;

	a_assert(pTableRegister);

	trace(4, T("DB: Registering database table <%s>\n"), 
		pTableRegister->name);

/*
 *	Bump up the size of the table array
 */
	tid = hAllocEntry((void***) &dbListTables, 
		&dbMaxTables, sizeof(dbTable_t));	

/*
 *	Copy the table schema to the last spot in schema array
 */
	a_assert(dbListTables);
	pTable = dbListTables[tid];
	a_assert(pTable);

/*
 *	Copy the name of the table
 */
	pTable->name = bstrdup(B_L, pTableRegister->name);

/*
 *	Copy the number of columns
 */
	pTable->nColumns = pTableRegister->nColumns;

/*
 *	Copy the column definitions
 */
	if (pTable->nColumns > 0) {
		int i;
		pTable->columnNames = balloc(B_L, sizeof(char_t *) * pTable->nColumns);
		pTable->columnTypes = balloc(B_L, sizeof(int *) * pTable->nColumns);

		for (i = 0; (i < pTableRegister->nColumns); i++) {
			pTable->columnNames[i] = 
				bstrdup(B_L, pTableRegister->columnNames[i]);
			pTable->columnTypes[i] = pTableRegister->columnTypes[i];
		}

	} else {
		pTable->columnNames = NULL;
		pTable->columnTypes = NULL;
	}

/*
 *	Zero out the table's data (very important!)
 */
	pTable->nRows = 0;
	pTable->rows = NULL;

	return 0;
}

/******************************************************************************/
/*
 *	This is provided for compatibility with EMF.  Tables are "registered"
 *	with staticly defined schemas.  There is only one did in this package: 0.
 */

int dbOpen(char_t *tablename, char_t *filename, 
		   int (*gettime)(int did), int flags)
{
	basicProdDir = NULL;		
	basicDefaultDir = T(".");
	dbMaxTables = 0;
	dbListTables = NULL;
	return 0;
}

/******************************************************************************/
/*
 *	Delete all the rows of the tables, and all of the tables
 */

void dbClose(int did)
{
	int			table, column;
	dbTable_t	*pTable;

/*
 *	Before doing anything, delete all the contents of the database
 */
	dbZero(did);

/*
 *	Now delete the tables
 */
	for (table = 0; table < dbMaxTables; table++) {
		pTable = dbListTables[table];

		if (pTable != NULL) {
/*
 *			Delete the table schema
 */
			if (pTable->nColumns) {
				for (column = 0; column < pTable->nColumns; column++) {
					bfreeSafe(B_L, pTable->columnNames[column]);
				}
				bfreeSafe(B_L, pTable->columnNames);
				bfreeSafe(B_L, pTable->columnTypes);
			}
/*
 *			Delete the table name
 */
			bfreeSafe(B_L, pTable->name);
/*
 *			Free the table
 */
			bfreeSafe(B_L, pTable);
			hFree((void ***) &dbListTables, table);
		}
	}

	if (dbListTables) {
		bfree(B_L, dbListTables);
	}

/*
 *	Set the global table list to a safe value
 */
	dbListTables = NULL;
	dbMaxTables = 0;
}


/******************************************************************************/
/*
 *	Delete all the data records in all tables
 */

void dbZero(int did)
{
	int			table, row, column, nRows, nColumns;
	int			*pRow;
	dbTable_t	*pTable;

/*
 *	Delete all data from all tables
 */
	for (table = 0; table < dbMaxTables; table++) {
		pTable = dbListTables[table];
/*
 *		Delete the row data contained within the schema
 */
		if (pTable) {
			nColumns = pTable->nColumns;
			nRows = pTable->nRows;
			for (row = 0; row < nRows; row++) {
				pRow = pTable->rows[row];
				if (pRow) {
/*
 *					Only delete the contents of rows not previously deleted!
 */
					for (column = 0; column < nColumns; column++) {
						if (pTable->columnTypes[column] == T_STRING) {
							bfreeSafe(B_L, (char_t *)(pRow[column]));
							pRow[column] = (int)NULL;
						}
					}

					bfreeSafe(B_L, pRow);
					hFree((void ***) &pTable->rows, row);
				}
			}

			pTable->rows = NULL;
			pTable->nRows = 0;
		}
	}
}

/******************************************************************************/
/*
 *	Find the a row in the table with the given string in the given column
 */

int dbSearchStr(int did, char_t *tablename, 
	char_t *colName, char_t *value, int flags)
{
	int			tid, nRows, nColumns, column;
   int match = 0;
	dbTable_t	*pTable;

	a_assert(tablename);
	a_assert(colName);
	a_assert(value);

	tid = dbGetTableId(0, tablename);
	a_assert(tid >= 0);

	if ((tid >= 0) && (tid < dbMaxTables) && (dbListTables[tid] != NULL)) {
		pTable = dbListTables[tid];
	} else {
		return DB_ERR_TABLE_NOT_FOUND;
	}
	
	nColumns = pTable->nColumns;
	nRows = pTable->nRows;
	column = GetColumnIndex(tid, colName);
	a_assert (column >= 0);

	if (column >= 0) {
		char_t	*compareVal;
		int		row, *pRow;
/*
 *		Scan through rows until we find a match.
 *		Note that some of these rows may be deleted!
 */
		row = 0;
		while (row < nRows) {
			pRow = pTable->rows[row];
			if (pRow) {
				compareVal = (char_t *)(pRow[column]); 
            if (NULL != compareVal)
            {
              if (DB_CASE_INSENSITIVE == flags)
              {
                 match = gstricmp(compareVal, value);
              }
              else
              {
                 match = gstrcmp(compareVal, value);
              }
              if (0 == match)
              {
                 return row;
              }
            }
			}
			row++;
		}
	} else { 
/*
 *		Return -2 if search column was not found
 */
		trace(3, T("DB: Unable to find column <%s> in table <%s>\n"), 
			colName, tablename);
		return DB_ERR_COL_NOT_FOUND;
	}

	return -1;
}

/******************************************************************************/
/*
 *	Add a new row to the given table.  Return the new row ID.
 */

int dbAddRow(int did, char_t *tablename)
{
	int			tid, size;
	dbTable_t	*pTable;

	a_assert(tablename);

	tid = dbGetTableId(0, tablename);
	a_assert(tid >= 0);

	if ((tid >= 0) && (tid < dbMaxTables) && (dbListTables[tid] != NULL)) {
		pTable = dbListTables[tid];
	} else {
		return DB_ERR_TABLE_NOT_FOUND;
	}

	a_assert(pTable);

	if (pTable) {
		trace(5, T("DB: Adding a row to table <%s>\n"), tablename);

		size = pTable->nColumns * max(sizeof(int), sizeof(char_t *));
		return hAllocEntry((void***) &(pTable->rows), &(pTable->nRows), size);
	} 

	return -1;
}

/******************************************************************************/
/*
 *	Delete a row in the table.  
 */

int dbDeleteRow(int did, char_t *tablename, int row)
{
	int			tid, nColumns, nRows;
	dbTable_t	*pTable;

	a_assert(tablename);
	tid = dbGetTableId(0, tablename);
	a_assert(tid >= 0);

	if ((tid >= 0) && (tid < dbMaxTables) && (dbListTables[tid] != NULL)) {
		pTable = dbListTables[tid];
	} else {
		return DB_ERR_TABLE_NOT_FOUND;
	}

	nColumns = pTable->nColumns;
	nRows = pTable->nRows;

	if ((row >= 0) && (row < nRows)) {
		int *pRow = pTable->rows[row];

		if (pRow) {
			int	column = 0;
/*
 *			Free up any allocated strings
 */
			while (column < nColumns) {
				if (pRow[column] && 
					(pTable->columnTypes[column] == T_STRING)) {
					bfree(B_L, (char_t *)pRow[column]);
				}

				column++;
			}
/*
 *			Zero out the row for safety
 */
			memset(pRow, 0, nColumns * max(sizeof(int), sizeof(char_t *)));

			bfreeSafe(B_L, pRow);
			pTable->nRows = hFree((void ***)&pTable->rows, row);
			trace(5, T("DB: Deleted row <%d> from table <%s>\n"), 
				row, tablename);
		}
		return 0;
	} else {
		trace(3, T("DB: Unable to delete row <%d> from table <%s>\n"), 
			row, tablename);
	}
	
	return -1;
}

/*****************************************************************************/
/*
 *	Grow the rows in the table to the nominated size. 
 */

int dbSetTableNrow(int did, char_t *tablename, int nNewRows)
{
	int			nRet, tid, nRows, nColumns;
	dbTable_t	*pTable;

	a_assert(tablename);
	tid = dbGetTableId(0, tablename);
	a_assert(tid >= 0) ;

	if ((tid >= 0) && (tid < dbMaxTables) && (dbListTables[tid] != NULL)) {
		pTable = dbListTables[tid];
	} else {
		return DB_ERR_TABLE_NOT_FOUND;
	}

	nRet = -1;

	a_assert(pTable);
	if (pTable) {
		nColumns = pTable->nColumns;
		nRows = pTable->nRows;
		nRet = 0;

		if (nRows >= nNewRows) {
/*		
 *		If number of rows already allocated exceeds requested number, do nothing
 */
			trace(4, T("DB: Ignoring row set to <%d> in table <%s>\n"),
				nNewRows, tablename);
		} else {
			trace(4, T("DB: Setting rows to <%d> in table <%s>\n"), 
				nNewRows, tablename);
			while (pTable->nRows < nNewRows) {
				if (dbAddRow(did, tablename) < 0) {
					return -1;
				}
			}
		}
	} 

	return nRet;
}

/******************************************************************************/
/*
 *	Return the number of rows in the given table
 */

int dbGetTableNrow(int did, char_t *tablename)
{
	int tid;
	
	a_assert(tablename);
	tid = dbGetTableId(did, tablename);

	if ((tid >= 0) && (tid < dbMaxTables) && (dbListTables[tid] != NULL)) {
		return (dbListTables[tid])->nRows;
	} else {
		return -1;
	}
}

/******************************************************************************/
/*
 *	Do table driven read of the database
 */

int dbReadInt(int did, char_t *table, char_t *column, int row, int *returnValue)
{
	int			colIndex, *pRow, tid;
	dbTable_t	*pTable;
	
	a_assert(table);
	a_assert(column);
	a_assert(returnValue);

	tid = dbGetTableId(0, table);
	a_assert(tid >= 0);

/*
 *	Return -6 if table is not found
 */
	if (tid < 0) {
		return DB_ERR_TABLE_NOT_FOUND;
	}

/*
 *	Return -7 if table id has been deleted
 */
	pTable = dbListTables[tid];
	if (pTable == NULL) {
		return DB_ERR_TABLE_DELETED;
	}

	a_assert(row >= 0);

	if ((row >= 0) && (row < pTable->nRows)) {
		colIndex = GetColumnIndex(tid, column);
		a_assert(colIndex >= 0);

		if (colIndex >= 0) {
			pRow = pTable->rows[row];
			if (pRow) {
				*returnValue = pRow[colIndex];
				return 0;
			}  
			return DB_ERR_ROW_DELETED;
		}
		return DB_ERR_COL_NOT_FOUND;
	}

	return DB_ERR_ROW_NOT_FOUND;
}

/******************************************************************************/
/*
 *	dbReadStr calls dbReadInt to do table driven read of database
 */

int dbReadStr(int did, char_t *table, char_t *column, int row,
		char_t **returnValue)
{
	return dbReadInt(did, table, column, row, (int *)returnValue);
}

/******************************************************************************/
/*
 *	The dbWriteInt function writes a value into a table at a given row and
 *	column.  The existence of the row and column is verified before the 
 *	write.  0 is returned on succes, -1 is returned on error.
 */

int dbWriteInt(int did, char_t *table, char_t *column, int row, int iData)
{