Adding upstream version 1.6.3.upstream/1.6.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 584 insertions, 0 deletions

diff --git a/dbm/sdbm/sdbm.c b/dbm/sdbm/sdbm.c
new file mode 100644
index 0000000..a62b009
--- /dev/null
+++ b/dbm/sdbm/sdbm.c
@@ -0,0 +1,584 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * sdbm - ndbm work-alike hashed database library
+ * based on Per-Aake Larson's Dynamic Hashing algorithms. BIT 18 (1978).
+ * author: oz@nexus.yorku.ca
+ * ex-public domain, ported to APR for Apache 2
+ * core routines
+ */
+
+#include "apr.h"
+#include "apr_file_io.h"
+#include "apr_strings.h"
+#include "apr_errno.h"
+#include "apr_sdbm.h"
+
+#include "sdbm_tune.h"
+#include "sdbm_pair.h"
+#include "sdbm_private.h"
+
+#include <string.h>     /* for memset() */
+#include <stdlib.h>     /* for malloc() and free() */
+
+/*
+ * forward
+ */
+static int getdbit (apr_sdbm_t *, long);
+static apr_status_t setdbit(apr_sdbm_t *, long);
+static apr_status_t getpage(apr_sdbm_t *db, long, int, int);
+static apr_status_t getnext(apr_sdbm_datum_t *key, apr_sdbm_t *db);
+static apr_status_t makroom(apr_sdbm_t *, long, int);
+
+/*
+ * useful macros
+ */
+#define bad(x)		((x).dptr == NULL || (x).dsize <= 0)
+#define exhash(item)	sdbm_hash((item).dptr, (item).dsize)
+
+#define OFF_PAG(off)	(apr_off_t) (off) * PBLKSIZ
+#define OFF_DIR(off)	(apr_off_t) (off) * DBLKSIZ
+
+static const long masks[] = {
+        000000000000, 000000000001, 000000000003, 000000000007,
+        000000000017, 000000000037, 000000000077, 000000000177,
+        000000000377, 000000000777, 000000001777, 000000003777,
+        000000007777, 000000017777, 000000037777, 000000077777,
+        000000177777, 000000377777, 000000777777, 000001777777,
+        000003777777, 000007777777, 000017777777, 000037777777,
+        000077777777, 000177777777, 000377777777, 000777777777,
+        001777777777, 003777777777, 007777777777, 017777777777
+};
+
+const apr_sdbm_datum_t sdbm_nullitem = { NULL, 0 };
+
+static apr_status_t database_cleanup(void *data)
+{
+    apr_sdbm_t *db = data;
+
+    /*
+     * Can't rely on apr_sdbm_unlock, since it will merely
+     * decrement the refcnt if several locks are held.
+     */
+    if (db->flags & (SDBM_SHARED_LOCK | SDBM_EXCLUSIVE_LOCK))
+        (void) apr_file_unlock(db->dirf);
+    (void) apr_file_close(db->dirf);
+    (void) apr_file_close(db->pagf);
+    free(db);
+
+    return APR_SUCCESS;
+}
+
+static apr_status_t prep(apr_sdbm_t **pdb, const char *dirname, const char *pagname,
+                         apr_int32_t flags, apr_fileperms_t perms, apr_pool_t *p)
+{
+    apr_sdbm_t *db;
+    apr_status_t status;
+
+    *pdb = NULL;
+
+    db = malloc(sizeof(*db));
+    memset(db, 0, sizeof(*db));
+    db->pagbno = -1L;
+
+    db->pool = p;
+
+    /*
+     * adjust user flags so that WRONLY becomes RDWR, 
+     * as required by this package. Also set our internal
+     * flag for RDONLY if needed.
+     */
+    if (!(flags & APR_FOPEN_WRITE)) {
+        db->flags |= SDBM_RDONLY;
+    }
+
+    /*
+     * adjust the file open flags so that we handle locking
+     * on our own (don't rely on any locking behavior within
+     * an apr_file_t, in case it's ever introduced, and set
+     * our own flag.
+     */
+    if (flags & APR_FOPEN_SHARELOCK) {
+        db->flags |= SDBM_SHARED;
+        flags &= ~APR_FOPEN_SHARELOCK;
+    }
+
+    flags |= APR_FOPEN_BINARY | APR_FOPEN_READ;
+
+    /*
+     * open the files in sequence, and stat the dirfile.
+     * If we fail anywhere, undo everything, return NULL.
+     */
+
+    if ((status = apr_file_open(&db->dirf, dirname, flags, perms, p))
+                != APR_SUCCESS)
+        goto error;
+
+    if ((status = apr_file_open(&db->pagf, pagname, flags, perms, p))
+                != APR_SUCCESS)
+        goto error;
+
+    if ((status = apr_sdbm_lock(db, (db->flags & SDBM_RDONLY) 
+                                        ? APR_FLOCK_SHARED
+                                        : APR_FLOCK_EXCLUSIVE))
+                != APR_SUCCESS)
+        goto error;
+
+    /* apr_pcalloc zeroed the buffers
+     * apr_sdbm_lock stated the dirf->size and invalidated the cache
+     */
+
+    /*
+     * if we are opened in SHARED mode, unlock ourself 
+     */
+    if (db->flags & SDBM_SHARED)
+        if ((status = apr_sdbm_unlock(db)) != APR_SUCCESS)
+            goto error;
+
+    /* make sure that we close the database at some point */
+    apr_pool_cleanup_register(p, db, database_cleanup, apr_pool_cleanup_null);
+
+    /* Done! */
+    *pdb = db;
+    return APR_SUCCESS;
+
+error:
+    if (db->dirf && db->pagf)
+        (void) apr_sdbm_unlock(db);
+    if (db->dirf != NULL)
+        (void) apr_file_close(db->dirf);
+    if (db->pagf != NULL) {
+        (void) apr_file_close(db->pagf);
+    }
+    free(db);
+    return status;
+}
+
+APU_DECLARE(apr_status_t) apr_sdbm_open(apr_sdbm_t **db, const char *file, 
+                                        apr_int32_t flags, 
+                                        apr_fileperms_t perms, apr_pool_t *p)
+{
+    char *dirname = apr_pstrcat(p, file, APR_SDBM_DIRFEXT, NULL);
+    char *pagname = apr_pstrcat(p, file, APR_SDBM_PAGFEXT, NULL);
+    
+    return prep(db, dirname, pagname, flags, perms, p);
+}
+
+APU_DECLARE(apr_status_t) apr_sdbm_close(apr_sdbm_t *db)
+{
+    return apr_pool_cleanup_run(db->pool, db, database_cleanup);
+}
+
+APU_DECLARE(apr_status_t) apr_sdbm_fetch(apr_sdbm_t *db, apr_sdbm_datum_t *val,
+                                         apr_sdbm_datum_t key)
+{
+    apr_status_t status;
+    
+    if (db == NULL || bad(key))
+        return APR_EINVAL;
+
+    if ((status = apr_sdbm_lock(db, APR_FLOCK_SHARED)) != APR_SUCCESS)
+        return status;
+
+    if ((status = getpage(db, exhash(key), 0, 1)) == APR_SUCCESS) {
+        *val = getpair(db->pagbuf, key);
+        /* ### do we want a not-found result? */
+    }
+
+    (void) apr_sdbm_unlock(db);
+
+    return status;
+}
+
+static apr_status_t write_page(apr_sdbm_t *db, const char *buf, long pagno)
+{
+    apr_status_t status;
+    apr_off_t off = OFF_PAG(pagno);
+    
+    if ((status = apr_file_seek(db->pagf, APR_SET, &off)) == APR_SUCCESS)
+        status = apr_file_write_full(db->pagf, buf, PBLKSIZ, NULL);
+
+    return status;
+}
+
+APU_DECLARE(apr_status_t) apr_sdbm_delete(apr_sdbm_t *db, 
+                                          const apr_sdbm_datum_t key)
+{
+    apr_status_t status;
+    
+    if (db == NULL || bad(key))
+        return APR_EINVAL;
+    if (apr_sdbm_rdonly(db))
+        return APR_EINVAL;
+    
+    if ((status = apr_sdbm_lock(db, APR_FLOCK_EXCLUSIVE)) != APR_SUCCESS)
+        return status;
+
+    if ((status = getpage(db, exhash(key), 0, 1)) == APR_SUCCESS) {
+        if (!delpair(db->pagbuf, key))
+            /* ### should we define some APRUTIL codes? */
+            status = APR_EGENERAL;
+        else
+            status = write_page(db, db->pagbuf, db->pagbno);
+    }
+
+    (void) apr_sdbm_unlock(db);
+
+    return status;
+}
+
+APU_DECLARE(apr_status_t) apr_sdbm_store(apr_sdbm_t *db, apr_sdbm_datum_t key,
+                                         apr_sdbm_datum_t val, int flags)
+{
+    int need;
+    register long hash;
+    apr_status_t status;
+    
+    if (db == NULL || bad(key))
+        return APR_EINVAL;
+    if (apr_sdbm_rdonly(db))
+        return APR_EINVAL;
+    need = key.dsize + val.dsize;
+    /*
+     * is the pair too big (or too small) for this database ??
+     */
+    if (need < 0 || need > PAIRMAX)
+        return APR_EINVAL;
+
+    if ((status = apr_sdbm_lock(db, APR_FLOCK_EXCLUSIVE)) != APR_SUCCESS)
+        return status;
+
+    if ((status = getpage(db, (hash = exhash(key)), 0, 1)) == APR_SUCCESS) {
+
+        /*
+         * if we need to replace, delete the key/data pair
+         * first. If it is not there, ignore.
+         */
+        if (flags == APR_SDBM_REPLACE)
+            (void) delpair(db->pagbuf, key);
+        else if (!(flags & APR_SDBM_INSERTDUP) && duppair(db->pagbuf, key)) {
+            status = APR_EEXIST;
+            goto error;
+        }
+        /*
+         * if we do not have enough room, we have to split.
+         */
+        if (!fitpair(db->pagbuf, need))
+            if ((status = makroom(db, hash, need)) != APR_SUCCESS)
+                goto error;
+        /*
+         * we have enough room or split is successful. insert the key,
+         * and update the page file.
+         */
+        (void) putpair(db->pagbuf, key, val);
+
+        status = write_page(db, db->pagbuf, db->pagbno);
+    }
+
+error:
+    (void) apr_sdbm_unlock(db);    
+
+    return status;
+}
+
+/*
+ * makroom - make room by splitting the overfull page
+ * this routine will attempt to make room for SPLTMAX times before
+ * giving up.
+ */
+static apr_status_t makroom(apr_sdbm_t *db, long hash, int need)
+{
+    long newp;
+    char twin[PBLKSIZ];
+    char *pag = db->pagbuf;
+    char *new = twin;
+    register int smax = SPLTMAX;
+    apr_status_t status;
+
+    do {
+        /*
+         * split the current page
+         */
+        (void) splpage(pag, new, db->hmask + 1);
+        /*
+         * address of the new page
+         */
+        newp = (hash & db->hmask) | (db->hmask + 1);
+
+        /*
+         * write delay, read avoidence/cache shuffle:
+         * select the page for incoming pair: if key is to go to the new page,
+         * write out the previous one, and copy the new one over, thus making
+         * it the current page. If not, simply write the new page, and we are
+         * still looking at the page of interest. current page is not updated
+         * here, as sdbm_store will do so, after it inserts the incoming pair.
+         */
+        if (hash & (db->hmask + 1)) {
+            if ((status = write_page(db, db->pagbuf, db->pagbno)) 
+                        != APR_SUCCESS)
+                return status;
+                    
+            db->pagbno = newp;
+            (void) memcpy(pag, new, PBLKSIZ);
+        }
+        else {
+            if ((status = write_page(db, new, newp)) != APR_SUCCESS)
+                return status;
+        }
+
+        if ((status = setdbit(db, db->curbit)) != APR_SUCCESS)
+            return status;
+        /*
+         * see if we have enough room now
+         */
+        if (fitpair(pag, need))
+            return APR_SUCCESS;
+        /*
+         * try again... update curbit and hmask as getpage would have
+         * done. because of our update of the current page, we do not
+         * need to read in anything. BUT we have to write the current
+         * [deferred] page out, as the window of failure is too great.
+         */
+        db->curbit = 2 * db->curbit
+                   + ((hash & (db->hmask + 1)) ? 2 : 1);
+        db->hmask |= db->hmask + 1;
+            
+        if ((status = write_page(db, db->pagbuf, db->pagbno))
+                    != APR_SUCCESS)
+            return status;
+            
+    } while (--smax);
+
+    /*
+     * if we are here, this is real bad news. After SPLTMAX splits,
+     * we still cannot fit the key. say goodnight.
+     */
+#if 0
+    (void) write(2, "sdbm: cannot insert after SPLTMAX attempts.\n", 44);
+#endif
+    /* ### ENOSPC not really appropriate but better than nothing */
+    return APR_ENOSPC;
+
+}
+
+/* Reads 'len' bytes from file 'f' at offset 'off' into buf.
+ * 'off' is given relative to the start of the file.
+ * If 'create' is asked and EOF is returned while reading, this is taken
+ * as success (i.e. a cleared buffer is returned).
+ */
+static apr_status_t read_from(apr_file_t *f, void *buf, 
+                              apr_off_t off, apr_size_t len,
+                              int create)
+{
+    apr_status_t status;
+
+    if ((status = apr_file_seek(f, APR_SET, &off)) != APR_SUCCESS ||
+        ((status = apr_file_read_full(f, buf, len, NULL)) != APR_SUCCESS)) {
+        /* if EOF is reached, pretend we read all zero's */
+        if (status == APR_EOF && create) {
+            memset(buf, 0, len);
+            status = APR_SUCCESS;
+        }
+    }
+
+    return status;
+}
+
+/*
+ * the following two routines will break if
+ * deletions aren't taken into account. (ndbm bug)
+ */
+APU_DECLARE(apr_status_t) apr_sdbm_firstkey(apr_sdbm_t *db, 
+                                            apr_sdbm_datum_t *key)
+{
+    apr_status_t status;
+    
+    if ((status = apr_sdbm_lock(db, APR_FLOCK_SHARED)) != APR_SUCCESS)
+        return status;
+
+    /*
+     * start at page 0
+     */
+    if ((status = getpage(db, 0, 1, 1)) == APR_SUCCESS) {
+        db->blkptr = 0;
+        db->keyptr = 0;
+        status = getnext(key, db);
+    }
+
+    (void) apr_sdbm_unlock(db);
+
+    return status;
+}
+
+APU_DECLARE(apr_status_t) apr_sdbm_nextkey(apr_sdbm_t *db, 
+                                           apr_sdbm_datum_t *key)
+{
+    apr_status_t status;
+    
+    if ((status = apr_sdbm_lock(db, APR_FLOCK_SHARED)) != APR_SUCCESS)
+        return status;
+
+    status = getnext(key, db);
+
+    (void) apr_sdbm_unlock(db);
+
+    return status;
+}
+
+/*
+ * all important binary tree traversal
+ */
+static apr_status_t getpage(apr_sdbm_t *db, long hash, int by_num, int create)
+{
+    apr_status_t status;
+    register long pagb;
+
+    if (by_num) {
+        pagb = hash;
+    }
+    else {
+        register int hbit = 0;
+        register long dbit = 0;
+
+        while (dbit < db->maxbno && getdbit(db, dbit))
+            dbit = 2 * dbit + ((hash & (1 << hbit++)) ? 2 : 1);
+        debug(("dbit: %d...", dbit));
+
+        db->curbit = dbit;
+        db->hmask = masks[hbit];
+
+        pagb = hash & db->hmask;
+    }
+
+    /*
+     * see if the block we need is already in memory.
+     * note: this lookaside cache has about 10% hit rate.
+     */
+    if (pagb != db->pagbno) { 
+        /*
+         * note: here, we assume a "hole" is read as 0s.
+         * if not, must zero pagbuf first.
+         * ### joe: this assumption was surely never correct? but
+         * ### we make it so in read_from anyway.
+         */
+        if ((status = read_from(db->pagf, db->pagbuf,
+                                OFF_PAG(pagb), PBLKSIZ,
+                                create)) != APR_SUCCESS)
+            return status;
+
+        if (!chkpage(db->pagbuf))
+            return APR_ENOSPC; /* ### better error? */
+
+        db->pagbno = pagb;
+
+        debug(("pag read: %d\n", pagb));
+    }
+    return APR_SUCCESS;
+}
+
+static int getdbit(apr_sdbm_t *db, long dbit)
+{
+    register long c;
+    register long dirb;
+
+    c = dbit / BYTESIZ;
+    dirb = c / DBLKSIZ;
+
+    if (dirb != db->dirbno) {
+        if (read_from(db->dirf, db->dirbuf,
+                      OFF_DIR(dirb), DBLKSIZ,
+                      1) != APR_SUCCESS)
+            return 0;
+
+        db->dirbno = dirb;
+
+        debug(("dir read: %d\n", dirb));
+    }
+
+    return db->dirbuf[c % DBLKSIZ] & (1 << dbit % BYTESIZ);
+}
+
+static apr_status_t setdbit(apr_sdbm_t *db, long dbit)
+{
+    register long c;
+    register long dirb;
+    apr_status_t status;
+    apr_off_t off;
+
+    c = dbit / BYTESIZ;
+    dirb = c / DBLKSIZ;
+
+    if (dirb != db->dirbno) {
+        if ((status = read_from(db->dirf, db->dirbuf,
+                                OFF_DIR(dirb), DBLKSIZ,
+                                1)) != APR_SUCCESS)
+            return status;
+
+        db->dirbno = dirb;
+        
+        debug(("dir read: %d\n", dirb));
+    }
+
+    db->dirbuf[c % DBLKSIZ] |= (1 << dbit % BYTESIZ);
+
+    if (dbit >= db->maxbno)
+        db->maxbno += DBLKSIZ * BYTESIZ;
+
+    off = OFF_DIR(dirb);
+    if ((status = apr_file_seek(db->dirf, APR_SET, &off)) == APR_SUCCESS)
+        status = apr_file_write_full(db->dirf, db->dirbuf, DBLKSIZ, NULL);
+
+    return status;
+}
+
+/*
+* getnext - get the next key in the page, and if done with
+* the page, try the next page in sequence
+*/
+static apr_status_t getnext(apr_sdbm_datum_t *key, apr_sdbm_t *db)
+{
+    apr_status_t status;
+    for (;;) {
+        db->keyptr++;
+        *key = getnkey(db->pagbuf, db->keyptr);
+        if (key->dptr != NULL)
+            return APR_SUCCESS;
+        /*
+         * we either run out, or there is nothing on this page..
+         * try the next one... If we lost our position on the
+         * file, we will have to seek.
+         */
+        db->blkptr++;
+        db->keyptr = 0;
+
+        /* ### EOF acceptable here too? */
+        if ((status = getpage(db, db->blkptr, 1, 0)) != APR_SUCCESS)
+            return status;
+    }
+
+    /* NOTREACHED */
+}
+
+
+APU_DECLARE(int) apr_sdbm_rdonly(apr_sdbm_t *db)
+{
+    /* ### Should we return true if the first lock is a share lock,
+     *     to reflect that apr_sdbm_store and apr_sdbm_delete will fail?
+     */
+    return (db->flags & SDBM_RDONLY) != 0;
+}
+