+++ /dev/null
-/* $Id: memory.c,v 1.18 2002-08-02 19:26:56 adam Exp $
- Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002
- Index Data Aps
-
-This file is part of the Zebra server.
-
-Zebra is free software; you can redistribute it and/or modify it under
-the terms of the GNU General Public License as published by the Free
-Software Foundation; either version 2, or (at your option) any later
-version.
-
-Zebra is distributed in the hope that it will be useful, but WITHOUT ANY
-WARRANTY; without even the implied warranty of MERCHANTABILITY or
-FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
-for more details.
-
-You should have received a copy of the GNU General Public License
-along with Zebra; see the file LICENSE.zebra. If not, write to the
-Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA.
-*/
-
-
-
-/*
- * This module accesses and rearranges the records of the tables.
- */
-
-#include <assert.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <zebrautl.h>
-#include <isam.h>
-
-int is_mbuf_size[3] = { 0, 1024, 4096 };
-
-static is_mblock *mblock_tmplist = 0, *mblock_freelist = 0;
-static is_mbuf *mbuf_freelist[3] = {0, 0, 0};
-
-#define MALLOC_CHUNK 20
-
-is_mblock *xmalloc_mblock()
-{
- is_mblock *tmp;
- int i;
-
- if (!mblock_freelist)
- {
- mblock_freelist = (is_mblock *)
- xmalloc(sizeof(is_mblock) * MALLOC_CHUNK);
- for (i = 0; i < MALLOC_CHUNK - 1; i++)
- mblock_freelist[i].next = &mblock_freelist[i+1];
- mblock_freelist[i].next = 0;
- }
- tmp = mblock_freelist;
- mblock_freelist = mblock_freelist->next;
- tmp->next = 0;
- tmp->state = IS_MBSTATE_UNREAD;
- tmp->data = 0;
- return tmp;
-}
-
-is_mbuf *xmalloc_mbuf(int type)
-{
- is_mbuf *tmp;
-
- if (mbuf_freelist[type])
- {
- tmp = mbuf_freelist[type];
- mbuf_freelist[type] = tmp->next;
- }
- else
- {
- tmp = (is_mbuf*) xmalloc(sizeof(is_mbuf) + is_mbuf_size[type]);
- tmp->type = type;
- }
- tmp->refcount = type ? 1 : 0;
- tmp->offset = tmp->num = tmp->cur_record = 0;
- tmp->data = (char*) tmp + sizeof(is_mbuf);
- tmp->next = 0;
- return tmp;
-}
-
-void xfree_mbuf(is_mbuf *p)
-{
- p->next = mbuf_freelist[p->type];
- mbuf_freelist[p->type] = p;
-}
-
-void xfree_mbufs(is_mbuf *l)
-{
- is_mbuf *p;
-
- while (l)
- {
- p = l->next;
- xfree_mbuf(l);
- l = p;
- }
-}
-
-void xfree_mblock(is_mblock *p)
-{
- xfree_mbufs(p->data);
- p->next = mblock_freelist;
- mblock_freelist = p;
-}
-
-void xrelease_mblock(is_mblock *p)
-{
- p->next = mblock_tmplist;
- mblock_tmplist = p;
-}
-
-void xfree_mblocks(is_mblock *l)
-{
- is_mblock *p;
-
- while (l)
- {
- p = l->next;
- xfree_mblock(l);
- l = p;
- }
-}
-
-void is_m_establish_tab(ISAM is, is_mtable *tab, ISAM_P pos)
-{
- tab->data = xmalloc_mblock();
- if (pos > 0)
- {
- tab->pos_type = is_type(pos);
- tab->num_records = -1;
- tab->data->num_records = -1;
- tab->data->diskpos = is_block(pos);
- tab->data->state = IS_MBSTATE_UNREAD;
- tab->data->data = 0;
- tab->cur_mblock = tab->data;
- tab->cur_mblock->cur_mbuf = 0;
- tab->last_mbuf = 0;
- }
- else /* new block */
- {
- tab->pos_type = 0;
- tab->num_records = 0;
- tab->data->num_records = 0;
- tab->data->diskpos = -1;
- tab->data->state = IS_MBSTATE_CLEAN;
- tab->data->data = xmalloc_mbuf(IS_MBUF_TYPE_LARGE);
- tab->cur_mblock = tab->data;
- tab->cur_mblock->cur_mbuf = tab->data->data;
- tab->cur_mblock->cur_mbuf->cur_record = 0;
- tab->last_mbuf = 0;
- }
- tab->is = is;
-}
-
-void is_m_release_tab(is_mtable *tab)
-{
- xfree_mblocks(tab->data);
- xfree_mblocks(mblock_tmplist);
- mblock_tmplist = 0;
-}
-
-void is_m_rewind(is_mtable *tab)
-{
- tab->cur_mblock = tab->data;
- if (tab->data)
- {
- tab->data->cur_mbuf = tab->data->data;
- if (tab->data->data)
- tab->data->data->cur_record = 0;
- }
-}
-
-static int read_current_full(is_mtable *tab, is_mblock *mblock)
-{
- if (is_p_read_full(tab, mblock) < 0)
- return -1;
- if (mblock->nextpos && !mblock->next)
- {
- mblock->next = xmalloc_mblock();
- mblock->next->diskpos = mblock->nextpos;
- mblock->next->state = IS_MBSTATE_UNREAD;
- mblock->next->data = 0;
- }
- mblock->cur_mbuf = mblock->data;
- mblock->data->cur_record = 0;
- return 0;
-}
-
-int is_m_read_full(is_mtable *tab, is_mblock *mblock)
-{
- return read_current_full(tab, mblock);
-}
-
-/*
- * replace the record right behind the pointer.
- */
-void is_m_replace_record(is_mtable *tab, const void *rec)
-{
- is_mbuf *mbuf = tab->cur_mblock->cur_mbuf;
-
- /* we assume that block is already in memory and that we are in the
- * right mbuf, and that it has space for us. */
- memcpy(mbuf->data + mbuf->offset + (mbuf->cur_record - 1) *
- is_keysize(tab->is), rec, is_keysize(tab->is));
- tab->cur_mblock->state = IS_MBSTATE_DIRTY;
-}
-
-/*
- * Delete the record right behind the pointer.
- */
-void is_m_delete_record(is_mtable *tab)
-{
- is_mbuf *mbuf, *inew;
-
- mbuf = tab->cur_mblock->cur_mbuf;
- if (mbuf->cur_record >= mbuf->num) /* top of mbuf */
- {
- mbuf->num--;
- mbuf->cur_record--;
- }
- else if (mbuf->cur_record == 1) /* beginning of mbuf */
- {
- mbuf->num--;
- mbuf->offset +=is_keysize(tab->is);
- mbuf->cur_record = 0;
- }
- else /* middle of mbuf */
- {
- /* insert block after current one */
- inew = xmalloc_mbuf(IS_MBUF_TYPE_SMALL);
- inew->next = mbuf->next;
- mbuf->next = inew;
-
- /* virtually transfer everything after current record to new one. */
- inew->data = mbuf->data;
- mbuf->refcount++;
- inew->offset = mbuf->offset + mbuf->cur_record * is_keysize(tab->is);
- inew->num = mbuf->num - mbuf->cur_record;
-
- /* old buf now only contains stuff before current record */
- mbuf->num = mbuf->cur_record -1;
- tab->cur_mblock->cur_mbuf = inew;
- }
- tab->num_records--;
- tab->cur_mblock->num_records--;
- tab->cur_mblock->state = tab->data->state = IS_MBSTATE_DIRTY;
-}
-
-int is_m_write_record(is_mtable *tab, const void *rec)
-{
- is_mbuf *mbuf, *oldnext, *dmbuf;
-
- /* make sure block is all in memory */
- if (tab->cur_mblock->state <= IS_MBSTATE_PARTIAL)
- if (read_current_full(tab, tab->cur_mblock) < 0)
- return -1;
- mbuf = tab->cur_mblock->cur_mbuf;
- if (mbuf->cur_record >= mbuf->num) /* top of mbuf */
- {
- /* mbuf is reference or full */
- if (mbuf->refcount != 1 || mbuf->offset + (mbuf->num + 1) *
- is_keysize(tab->is) > is_mbuf_size[mbuf->type])
- {
- oldnext = mbuf->next;
- mbuf->next = xmalloc_mbuf(IS_MBUF_TYPE_LARGE);
- mbuf->next->next = oldnext;
- mbuf = mbuf->next;
- tab->cur_mblock->cur_mbuf = mbuf;
- mbuf->cur_record = 0;
- }
- }
- else
- {
- oldnext = mbuf->next;
- mbuf->next = xmalloc_mbuf(IS_MBUF_TYPE_MEDIUM);
- mbuf->next->next = dmbuf = xmalloc_mbuf(IS_MBUF_TYPE_SMALL);
- dmbuf->data = mbuf->data;
- dmbuf->next = oldnext;
- dmbuf->offset = mbuf->offset + mbuf->cur_record * is_keysize(tab->is);
- dmbuf->num = mbuf->num - mbuf->cur_record;
- mbuf->num -= dmbuf->num;
- mbuf->refcount++;
- mbuf = tab->cur_mblock->cur_mbuf = mbuf->next;
- mbuf->cur_record = 0;
- }
- /*
- logf (LOG_DEBUG, "is_m_write_rec(rec == %d)", mbuf->cur_record);
- */
- memcpy(mbuf->data + mbuf->offset + mbuf->cur_record * is_keysize(tab->is),
- rec, is_keysize(tab->is));
- mbuf->num++;
- mbuf->cur_record++;
- tab->num_records++;
- tab->cur_mblock->num_records++;
- tab->cur_mblock->state = tab->data->state = IS_MBSTATE_DIRTY;
- return 0;
-}
-
-void is_m_unread_record(is_mtable *tab)
-{
- assert(tab->cur_mblock->cur_mbuf->cur_record);
- if (tab->last_mbuf)
- tab->cur_mblock->cur_mbuf = tab->last_mbuf;
- else
- tab->cur_mblock->cur_mbuf->cur_record--;
-}
-
-/*
- * non-destructive read.
- */
-int is_m_peek_record(is_mtable *tab, void *rec)
-{
- is_mbuf *mbuf;
- is_mblock *mblock;
-
- /* make sure block is all in memory */
- if (tab->cur_mblock->state <= IS_MBSTATE_PARTIAL)
- if (read_current_full(tab, tab->cur_mblock) < 0)
- return -1;
- mblock = tab->cur_mblock;
- mbuf = mblock->cur_mbuf;
- if (mbuf->cur_record >= mbuf->num) /* are we at end of mbuf? */
- {
- if (!mbuf->next) /* end of mblock */
- {
- if (mblock->next)
- {
- mblock = mblock->next;
- if (mblock->state <= IS_MBSTATE_PARTIAL)
- if (read_current_full(tab, mblock) < 0)
- return -1;
- mbuf = mblock->data;
- }
- else
- return 0; /* EOTable */
- }
- else
- mbuf = mbuf->next;
- mbuf->cur_record = 0;
- }
- memcpy(rec, mbuf->data + mbuf->offset + mbuf->cur_record *
- is_keysize(tab->is), is_keysize(tab->is));
- return 1;
-}
-
-int is_m_read_record(is_mtable *tab, void *buf, int keep)
-{
- is_mbuf *mbuf;
-
- /* make sure block is all in memory */
- if (tab->cur_mblock->state <= IS_MBSTATE_PARTIAL)
- if (read_current_full(tab, tab->cur_mblock) < 0)
- return -1;
- mbuf = tab->cur_mblock->cur_mbuf;
- if (mbuf->cur_record >= mbuf->num) /* are we at end of mbuf? */
- {
- if (!mbuf->next) /* end of mblock */
- {
- if (!keep && tab->cur_mblock->state == IS_MBSTATE_CLEAN &&
- tab->cur_mblock->diskpos > 0)
- {
- xfree_mbufs(tab->cur_mblock->data);
- tab->cur_mblock->data = 0;
- tab->cur_mblock->state = IS_MBSTATE_UNREAD;
- }
- if (tab->cur_mblock->next)
- {
- tab->cur_mblock = tab->cur_mblock->next;
- if (tab->cur_mblock->state <= IS_MBSTATE_PARTIAL)
- if (read_current_full(tab, tab->cur_mblock) < 0)
- return -1;
- tab->cur_mblock->cur_mbuf = mbuf = tab->cur_mblock->data;
- tab->last_mbuf = 0;
- }
- else
- return 0; /* EOTable */
- }
- else
- {
- tab->last_mbuf = mbuf;
- tab->cur_mblock->cur_mbuf = mbuf = mbuf->next;
- }
- mbuf->cur_record = 0;
- }
- else
- tab->last_mbuf = 0;
- memcpy(buf, mbuf->data + mbuf->offset + mbuf->cur_record *
- is_keysize(tab->is), is_keysize(tab->is));
- mbuf->cur_record++;
- return 1;
-}
-
-/*
- * TODO: optimize this function by introducing a higher-level search.
- */
-int is_m_seek_record(is_mtable *tab, const void *rec)
-{
- char peek[IS_MAX_RECORD];
- int rs;
-
- for (;;)
- {
- if (is_m_read_record(tab, &peek, 1) <= 0)
- return 1;
- if ((rs = (*tab->is->cmp)(peek, rec)) > 0)
- {
- is_m_unread_record(tab);
- return rs;
- }
- else if (rs == 0)
- return 0;
- }
-}
-
-int is_m_num_records(is_mtable *tab)
-{
- if (tab->data->state < IS_MBSTATE_PARTIAL)
- if (read_current_full(tab, tab->data) < 0)
- {
- logf (LOG_FATAL, "read full failed");
- exit(1);
- }
- return tab->num_records;
-}
projects / idzebra-moved-to-github.git / blobdiff