/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)rec_get.c	5.2 (Berkeley) 09/11/91";
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <errno.h>
#include <db.h>
#include <unistd.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "recno.h"

/*
 * __REC_GET -- Get a record from the btree.
 *
 * Parameters:
 *	dbp:	pointer to access method
 *	key:	key to find
 *	data:	data to return
 *	flag:	currently unused
 *
 * Returns:
 *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
 */
int
__rec_get(dbp, key, data, flags)
	const DB *dbp;
	const DBT *key;
	DBT *data;
	u_int flags;
{
	BTREE *t;
	EPG *e;
	recno_t nrec;
	int exact, status;

	if (flags || (nrec = *(recno_t *)key->data) == 0) {
		errno = EINVAL;
		return (RET_ERROR);
	}

	/*
	 * If we haven't seen this record yet, try to find it in the
	 * original file.
	 */
	t = dbp->internal;
	if (nrec > t->bt_nrecs && 
	   (status = t->bt_irec(t, nrec)) != RET_SUCCESS)
			return (status);

	--nrec;
	if ((e = __rec_search(t, nrec, SEARCH)) == NULL)
		return (RET_ERROR);

	if (!exact) {
		mpool_put(t->bt_mp, e->page, 0);
		return (RET_SPECIAL);
	}

	status = __rec_ret(t, e, data);
	mpool_put(t->bt_mp, e->page, 0);
	return (status);
}

/*
 * __REC_FPIPE -- Get fixed length records from a pipe.
 *
 * Parameters:
 *	t:	tree
 *	cnt:	records to read
 *
 * Returns:
 *	RET_ERROR, RET_SUCCESS
 */
int
__rec_fpipe(t, top)
	BTREE *t;
	recno_t top;
{
	static int eof;
	DBT data;
	recno_t nrec;
	size_t len;
	int ch;
	char *p;

	if (eof)
		return (RET_SPECIAL);

	data.data = t->bt_dbuf;
	data.size = t->bt_reclen;

	if (t->bt_dbufsz < t->bt_reclen) {
		if ((t->bt_dbuf = realloc(t->bt_dbuf, t->bt_reclen)) == NULL)
			return (RET_ERROR);
		t->bt_dbufsz = t->bt_reclen;
	}
	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
		for (p = t->bt_dbuf;; *p++ = ch)
			if ((ch = getc(t->bt_rfp)) == EOF || !len--) {
				if (__rec_iput(t, nrec, &data, 0)
				    != RET_SUCCESS)
					return (RET_ERROR);
				break;
			}
		if (ch == EOF)
			break;
	}
	if (nrec < top) {
		eof = 1;
		return (RET_SPECIAL);
	}
	return (RET_SUCCESS);
}

/*
 * __REC_VPIPE -- Get variable length records from a pipe.
 *
 * Parameters:
 *	t:	tree
 *	cnt:	records to read
 *
 * Returns:
 *	RET_ERROR, RET_SUCCESS
 */
int
__rec_vpipe(t, top)
	BTREE *t;
	recno_t top;
{
	static int eof;
	DBT data;
	recno_t nrec;
	index_t len;
	size_t sz;
	int bval, ch;
	char *p;

	if (eof)
		return (RET_SPECIAL);

	bval = t->bt_bval;
	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
		for (p = t->bt_dbuf, sz = t->bt_dbufsz;; *p++ = ch, --sz) {
			if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) {
				data.data = t->bt_dbuf;
				data.size = p - t->bt_dbuf;
				if (__rec_iput(t, nrec, &data, 0)
				    != RET_SUCCESS)
					return (RET_ERROR);
				break;
			}
			if (sz == 0) {
				len = p - t->bt_dbuf;
				sz = t->bt_dbufsz += 256;
				if ((t->bt_dbuf =
				    realloc(t->bt_dbuf, sz)) == NULL)
					return (RET_ERROR);
				p = t->bt_dbuf + len;
			}
		}
		if (ch == EOF)
			break;
	}
	if (nrec < top) {
		eof = 1;
		return (RET_SPECIAL);
	}
	return (RET_SUCCESS);
}

/*
 * __REC_FMAP -- Get fixed length records from a file.
 *
 * Parameters:
 *	t:	tree
 *	cnt:	records to read
 *
 * Returns:
 *	RET_ERROR, RET_SUCCESS
 */
int
__rec_fmap(t, top)
	BTREE *t;
	recno_t top;
{
	static int eof;
	DBT data;
	recno_t nrec;
	caddr_t sp, ep;
	size_t len;
	char *p;

	if (eof)
		return (RET_SPECIAL);

	sp = t->bt_smap;
	ep = t->bt_emap;
	data.data = t->bt_dbuf;
	data.size = t->bt_reclen;

	if (t->bt_dbufsz < t->bt_reclen) {
		if ((t->bt_dbuf = realloc(t->bt_dbuf, t->bt_reclen)) == NULL)
			return (RET_ERROR);
		t->bt_dbufsz = t->bt_reclen;
	}
	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
		if (sp >= ep) {
			eof = 1;
			return (RET_SPECIAL);
		}
		len = t->bt_reclen;
		for (p = t->bt_dbuf; sp < ep && len--; *p++ = *sp++);
		memset(p, t->bt_bval, len);
		if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
			return (RET_ERROR);
	}
	t->bt_smap = sp;
	return (RET_SUCCESS);
}

/*
 * __REC_VMAP -- Get variable length records from a file.
 *
 * Parameters:
 *	t:	tree
 *	cnt:	records to read
 *
 * Returns:
 *	RET_ERROR, RET_SUCCESS
 */
int
__rec_vmap(t, top)
	BTREE *t;
	recno_t top;
{
	static int eof;
	DBT data;
	caddr_t sp, ep;
	recno_t nrec;
	int bval;

	if (eof)
		return (RET_SPECIAL);

	sp = t->bt_smap;
	ep = t->bt_emap;
	bval = t->bt_bval;

	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
		if (sp >= ep) {
			eof = 1;
			return (RET_SPECIAL);
		}
		for (data.data = sp; sp < ep && *sp != bval; ++sp);
		data.size = sp - (caddr_t)data.data;
		if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
			return (RET_ERROR);
		++sp;
	}
	t->bt_smap = sp;
	return (RET_SUCCESS);
}