ecpglib.c

关系型数据库 Postgresql 6.5.2

/* Copyright comment */
/*
 * The aim is to get a simpler inteface to the database routines.
 * All the tidieous messing around with tuples is supposed to be hidden
 * by this function.
 */
/* Author: Linus Tolke
   (actually most if the code is "borrowed" from the distribution and just
   slightly modified)
 */

/* Taken over as part of PostgreSQL by Michael Meskes <[e-mail]>
   on Feb. 5th, 1998 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdarg.h>
#include <string.h>
#include <ctype.h>

#include <libpq-fe.h>
#include <libpq/pqcomm.h>
#include <ecpgtype.h>
#include <ecpglib.h>
#include <sqlca.h>

/* variables visible to the programs */
static struct sqlca sqlca_init =
{
	{'S', 'Q', 'L', 'C', 'A', ' ', ' ', ' '},
	sizeof(struct sqlca),
	0,
	{0, {0}},
	{'N', 'O', 'T', ' ', 'S', 'E', 'T', ' '},
	{0, 0, 0, 0, 0, 0},
	{0, 0, 0, 0, 0, 0, 0, 0},
	{0, 0, 0, 0, 0, 0, 0, 0}
};

struct sqlca sqlca =
{
	{'S', 'Q', 'L', 'C', 'A', ' ', ' ', ' '},
	sizeof(struct sqlca),
	0,
	{0, {0}},
	{'N', 'O', 'T', ' ', 'S', 'E', 'T', ' '},
	{0, 0, 0, 0, 0, 0},
	{0, 0, 0, 0, 0, 0, 0, 0},
	{0, 0, 0, 0, 0, 0, 0, 0}
};

static struct connection
{
	char	   *name;
	PGconn	   *connection;
	bool		committed;
	int			autocommit;
	struct connection *next;
}		   *all_connections = NULL, *actual_connection = NULL;

struct variable
{
	enum ECPGttype type;
	void	   *value;
	void	   *pointer;
	long		varcharsize;
	long		arrsize;
	long		offset;
	enum ECPGttype ind_type;
	void	   *ind_value;
	long		ind_varcharsize;
	long		ind_arrsize;
	long		ind_offset;
	struct variable *next;
};

struct statement
{
	int			lineno;
	char	   *command;
	struct connection *connection;
	struct variable *inlist;
	struct variable *outlist;
};

struct prepared_statement
{
	char	   *name;
	struct statement *stmt;
	struct prepared_statement *next;
}		   *prep_stmts = NULL;

struct auto_mem
{
	void	   *pointer;
	struct auto_mem *next;
}		   *auto_allocs = NULL;

static int	simple_debug = 0;
static FILE *debugstream = NULL;

static void
register_error(long code, char *fmt,...)
{
	va_list		args;
	struct auto_mem *am;

	sqlca.sqlcode = code;
	va_start(args, fmt);
	vsprintf(sqlca.sqlerrm.sqlerrmc, fmt, args);
	va_end(args);
	sqlca.sqlerrm.sqlerrml = strlen(sqlca.sqlerrm.sqlerrmc);

	/* free all memory we have allocated for the user */
	for (am = auto_allocs; am;)
	{
		struct auto_mem *act = am;

		am = am->next;
		free(act->pointer);
		free(act);
	}

	auto_allocs = NULL;
}

static struct connection *
get_connection(const char *connection_name)
{
	struct connection *con = all_connections;

	if (connection_name == NULL || strcmp(connection_name, "CURRENT") == 0)
		return actual_connection;

	for (; con && strcmp(connection_name, con->name) != 0; con = con->next);
	if (con)
		return con;
	else
		return NULL;
}

static void
ECPGfinish(struct connection * act)
{
	if (act != NULL)
	{
		ECPGlog("ECPGfinish: finishing %s.\n", act->name);
		PQfinish(act->connection);
		/* remove act from the list */
		if (act == all_connections)
			all_connections = act->next;
		else
		{
			struct connection *con;

			for (con = all_connections; con->next && con->next != act; con = con->next);
			if (con->next)
				con->next = act->next;
		}

		if (actual_connection == act)
			actual_connection = all_connections;

		free(act->name);
		free(act);
	}
	else
		ECPGlog("ECPGfinish: called an extra time.\n");
}

static char *
ecpg_alloc(long size, int lineno)
{
	char	   *new = (char *) calloc(1L, size);

	if (!new)
	{
		ECPGlog("out of memory\n");
		register_error(ECPG_OUT_OF_MEMORY, "Out of memory in line %d", lineno);
		return NULL;
	}

	memset(new, '\0', size);
	return (new);
}

static char *
ecpg_strdup(const char *string, int lineno)
{
	char	   *new = strdup(string);

	if (!new)
	{
		ECPGlog("out of memory\n");
		register_error(ECPG_OUT_OF_MEMORY, "Out of memory in line %d", lineno);
		return NULL;
	}

	return (new);
}

static void
add_mem(void *ptr, int lineno)
{
	struct auto_mem *am = (struct auto_mem *) ecpg_alloc(sizeof(struct auto_mem), lineno);

	am->next = auto_allocs;
	auto_allocs = am;
}

/* This function returns a newly malloced string that has the ' and \
   in the argument quoted with \.
 */
static
char *
quote_postgres(char *arg, int lineno)
{
	char	   *res = (char *) ecpg_alloc(2 * strlen(arg) + 1, lineno);
	int			i,
				ri;

	if (!res)
		return (res);

	for (i = 0, ri = 0; arg[i]; i++, ri++)
	{
		switch (arg[i])
		{
			case '\'':
			case '\\':
				res[ri++] = '\\';
			default:
				;
		}

		res[ri] = arg[i];
	}
	res[ri] = '\0';

	return res;
}

/*
 * create a list of variables
 * The variables are listed with input variables preceeding outputvariables
 * The end of each group is marked by an end marker.
 * per variable we list:
 * type - as defined in ecpgtype.h
 * value - where to store the data
 * varcharsize - length of string in case we have a stringvariable, else 0
 * arraysize - 0 for pointer (we don't know the size of the array),
 * 1 for simple variable, size for arrays
 * offset - offset between ith and (i+1)th entry in an array,
 * normally that means sizeof(type)
 * ind_type - type of indicator variable
 * ind_value - pointer to indicator variable
 * ind_varcharsize - empty
 * ind_arraysize -	arraysize of indicator array
 * ind_offset - indicator offset
 */
static bool
create_statement(int lineno, struct connection * connection, struct statement ** stmt, char *query, va_list ap)
{
	struct variable **list = &((*stmt)->inlist);
	enum ECPGttype type;

	if (!(*stmt = (struct statement *) ecpg_alloc(sizeof(struct statement), lineno)))
		return false;

	(*stmt)->command = query;
	(*stmt)->connection = connection;
	(*stmt)->lineno = lineno;

	list = &((*stmt)->inlist);

	type = va_arg(ap, enum ECPGttype);

	while (type != ECPGt_EORT)
	{
		if (type == ECPGt_EOIT)
			list = &((*stmt)->outlist);
		else
		{
			struct variable *var,
					   *ptr;

			if (!(var = (struct variable *) ecpg_alloc(sizeof(struct variable), lineno)))
				return false;

			var->type = type;
			var->pointer = va_arg(ap, void *);

			/* if variable is NULL, the statement hasn't been prepared */
			if (var->pointer == NULL)
			{
				ECPGlog("create_statement: invalid statement name\n");
				register_error(ECPG_INVALID_STMT, "Invalid statement name in line %d.", lineno);
				free(var);
				return false;
			}

			var->varcharsize = va_arg(ap, long);
			var->arrsize = va_arg(ap, long);
			var->offset = va_arg(ap, long);

			if (var->arrsize == 0 || var->varcharsize == 0)
				var->value = *((void **) (var->pointer));
			else
				var->value = var->pointer;

			var->ind_type = va_arg(ap, enum ECPGttype);
			var->ind_value = va_arg(ap, void *);
			var->ind_varcharsize = va_arg(ap, long);
			var->ind_arrsize = va_arg(ap, long);
			var->ind_offset = va_arg(ap, long);
			var->next = NULL;

			for (ptr = *list; ptr && ptr->next; ptr = ptr->next);

			if (ptr == NULL)
				*list = var;
			else
				ptr->next = var;
		}

		type = va_arg(ap, enum ECPGttype);
	}

	return (true);
}

static void
free_variable(struct variable * var)
{
	struct variable *var_next;

	if (var == (struct variable *) NULL)
		return;
	var_next = var->next;
	free(var);

	while (var_next)
	{
		var = var_next;
		var_next = var->next;
		free(var);
	}
}

static void
free_statement(struct statement * stmt)
{
	if (stmt == (struct statement *) NULL)
		return;
	free_variable(stmt->inlist);
	free_variable(stmt->outlist);
	free(stmt);
}

static char *
next_insert(char *text)
{
	char	   *ptr = text;
	bool		string = false;

	for (; *ptr != '\0' && (*ptr != '?' || string); ptr++)
		if (*ptr == '\'')
			string = string ? false : true;

	return (*ptr == '\0') ? NULL : ptr;
}

static bool
ECPGexecute(struct statement * stmt)
{
	bool		status = false;
	char	   *copiedquery;
	PGresult   *results;
	PGnotify   *notify;
	struct variable *var;

	memcpy((char *) &sqlca, (char *) &sqlca_init, sizeof(sqlca));

	copiedquery = ecpg_strdup(stmt->command, stmt->lineno);

	/*
	 * Now, if the type is one of the fill in types then we take the
	 * argument and enter that in the string at the first %s position.
	 * Then if there are any more fill in types we fill in at the next and
	 * so on.
	 */
	var = stmt->inlist;
	while (var)
	{
		char	   *newcopy;
		char	   *mallocedval = NULL;
		char	   *tobeinserted = NULL;
		char	   *p;
		char		buff[20];

		/*
		 * Some special treatment is needed for records since we want
		 * their contents to arrive in a comma-separated list on insert (I
		 * think).
		 */

		buff[0] = '\0';

		/* check for null value and set input buffer accordingly */
		switch (var->ind_type)
		{
			case ECPGt_short:
			case ECPGt_unsigned_short:
				if (*(short *) var->ind_value < 0)
					strcpy(buff, "null");
				break;
			case ECPGt_int:
			case ECPGt_unsigned_int:
				if (*(int *) var->ind_value < 0)
					strcpy(buff, "null");
				break;
			case ECPGt_long:
			case ECPGt_unsigned_long:
				if (*(long *) var->ind_value < 0L)
					strcpy(buff, "null");
				break;
			default:
				break;
		}

		if (*buff == '\0')
		{
			switch (var->type)
			{
				case ECPGt_short:
					sprintf(buff, "%d", *(short *) var->value);
					tobeinserted = buff;
					break;

				case ECPGt_int:
					sprintf(buff, "%d", *(int *) var->value);
					tobeinserted = buff;
					break;

				case ECPGt_unsigned_short:
					sprintf(buff, "%d", *(unsigned short *) var->value);
					tobeinserted = buff;
					break;

				case ECPGt_unsigned_int:
					sprintf(buff, "%d", *(unsigned int *) var->value);
					tobeinserted = buff;
					break;

				case ECPGt_long:
					sprintf(buff, "%ld", *(long *) var->value);
					tobeinserted = buff;
					break;

				case ECPGt_unsigned_long:
					sprintf(buff, "%ld", *(unsigned long *) var->value);
					tobeinserted = buff;
					break;

				case ECPGt_float:
					sprintf(buff, "%.14g", *(float *) var->value);
					tobeinserted = buff;
					break;

				case ECPGt_double:
					sprintf(buff, "%.14g", *(double *) var->value);