1 files changed, 394 insertions, 0 deletions

diff --git a/libetpan/src/data-types/chash.c b/libetpan/src/data-types/chash.c
new file mode 100644
index 0000000..a89eb91
--- a/dev/null
+++ b/libetpan/src/data-types/chash.c
@@ -0,0 +1,394 @@
+/*
+ * libEtPan! -- a mail stuff library
+ *
+ * chash - Implements generic hash tables.
+ *
+ * Copyright (c) 1999-2005, Gaël Roualland <gael.roualland@iname.com>
+ * interface changes - 2005 - DINH Viet Hoa
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the libEtPan! project nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * $Id$
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "chash.h"
+
+/* This defines the maximum (average) number of entries per bucket.
+   The hash is resized everytime inserting an entry makes the
+   average go over that value. */
+#define CHASH_MAXDEPTH    3
+
+static inline unsigned int chash_func(const char * key, unsigned int len) {
+#if 0
+  register unsigned int c = 0, t;
+  register const char * k = key;
+  
+  while (len--) {
+    c += (c << 4) + *k++;
+    if ((t = c & 0xF0000000)) {
+      c ^= t >> 24;
+      c ^= t;
+    }
+  }
+  return c;
+#endif
+  register unsigned int c = 5381;
+  register const char * k = key;
+  
+  while (len--) {
+    c = ((c << 5) + c) + *k++;
+  }
+  
+  return c;
+}
+
+static inline char * chash_dup(const void * data, unsigned int len)
+{
+  void * r;
+
+  r = (char *) malloc(len);
+  if (!r)
+    return NULL;
+  memcpy(r, data, len);
+  return r;
+}
+
+chash * chash_new(unsigned int size, int flags)
+{
+  chash * h;
+
+  h = (chash *) malloc(sizeof(chash));
+  if (h == NULL)
+    return NULL;
+
+  h->count = 0;
+  h->cells = (struct chashcell **) calloc(size, sizeof(struct chashcell *));
+  if (h->cells == NULL) {
+    free(h);
+    return NULL;
+  }
+  h->size = size;
+  h->copykey = flags & CHASH_COPYKEY;
+  h->copyvalue = flags & CHASH_COPYVALUE;
+  
+  return h;
+}
+
+int chash_get(chash * hash,
+              chashdatum * key, chashdatum * result)
+{
+  unsigned int func;
+  chashiter * iter;
+  
+  func = chash_func(key->data, key->len);
+
+  /* look for the key in existing cells */
+  iter = hash->cells[func % hash->size];
+  while (iter) {
+    if (iter->key.len == key->len && iter->func == func
+        && !memcmp(iter->key.data, key->data, key->len)) {
+      * result = iter->value; /* found */
+
+      return 0;
+    }
+    iter = iter->next;
+  }
+
+  return -1;
+}
+
+int chash_set(chash * hash,
+              chashdatum * key,
+              chashdatum * value,
+              chashdatum * oldvalue)
+{
+  unsigned int func, indx;
+  chashiter * iter, * cell;
+  int r;
+
+  if (hash->count > hash->size * CHASH_MAXDEPTH) {
+    r = chash_resize(hash, (hash->count / CHASH_MAXDEPTH) * 2 + 1);
+    if (r < 0)
+      goto err;
+  }
+
+  func = chash_func(key->data, key->len);
+  indx = func % hash->size;
+
+  /* look for the key in existing cells */
+  iter = hash->cells[indx];
+  while (iter) {
+    if (iter->key.len == key->len && iter->func == func
+        && !memcmp(iter->key.data, key->data, key->len)) {
+      /* found, replacing entry */
+      if (hash->copyvalue) {
+        char * data;
+
+        data = chash_dup(value->data, value->len);
+        if (data == NULL)
+          goto err;
+
+        free(iter->value.data);
+        iter->value.data = data;
+        iter->value.len = value->len;
+      } else {
+        if (oldvalue != NULL) {
+          oldvalue->data = iter->value.data;
+          oldvalue->len = iter->value.len;
+        }
+        iter->value.data = value->data;
+        iter->value.len = value->len;
+      }
+      if (!hash->copykey)
+        iter->key.data = key->data;
+
+      if (oldvalue != NULL) {
+        oldvalue->data = value->data;
+        oldvalue->len = value->len;
+      }
+
+      return 0;
+    }
+    iter = iter->next;
+  }
+  
+  if (oldvalue != NULL) {
+    oldvalue->data = NULL;
+    oldvalue->len = 0;
+  }
+  
+  /* not found, adding entry */
+  cell = (struct chashcell *) malloc(sizeof(struct chashcell));
+  if (cell == NULL)
+    goto err;
+
+  if (hash->copykey) {
+    cell->key.data = chash_dup(key->data, key->len);
+    if (cell->key.data == NULL)
+      goto free;
+  }
+  else
+    cell->key.data = key->data;
+
+  cell->key.len = key->len;
+  if (hash->copyvalue) {
+    cell->value.data = chash_dup(value->data, value->len);
+    if (cell->value.data == NULL)
+      goto free_key_data;
+  }
+  else
+    cell->value.data = value->data;
+
+  cell->value.len = value->len;
+  cell->func = func;
+  cell->next = hash->cells[indx];
+  hash->cells[indx] = cell;
+  hash->count++;
+
+  return 0;
+  
+ free_key_data:
+  if (hash->copykey)
+    free(cell->key.data);
+ free:
+  free(cell);
+ err:
+  return -1;
+}
+
+int chash_delete(chash * hash, chashdatum * key, chashdatum * oldvalue)
+{
+  /*  chashdatum result = { NULL, TRUE }; */
+  unsigned int func, indx;
+  chashiter * iter, * old;
+
+  /*  
+  if (!keylen)
+    keylen = strlen(key) + 1;  
+  */
+
+  func = chash_func(key->data, key->len);
+  indx = func % hash->size;
+
+  /* look for the key in existing cells */
+  old = NULL;
+  iter = hash->cells[indx];
+  while (iter) {
+    if (iter->key.len == key->len && iter->func == func
+        && !memcmp(iter->key.data, key->data, key->len)) {
+      /* found, deleting */
+      if (old)
+        old->next = iter->next;
+      else
+        hash->cells[indx] = iter->next;
+      if (hash->copykey)
+        free(iter->key.data);
+      if (hash->copyvalue)
+        free(iter->value.data);
+      else {
+        if (oldvalue != NULL) {
+          oldvalue->data = iter->value.data;
+          oldvalue->len = iter->value.len;
+        }
+      }
+      free(iter);
+      hash->count--;
+      return 0;
+    }
+    old = iter;
+    iter = iter->next;
+  }
+
+  return -1; /* not found */
+}
+
+void chash_free(chash * hash) {
+  unsigned int indx;
+  chashiter * iter, * next;
+
+  /* browse the hash table */
+  for(indx = 0; indx < hash->size; indx++) {
+    iter = hash->cells[indx];
+    while (iter) {
+      next = iter->next;
+      if (hash->copykey)
+        free(iter->key.data);
+      if (hash->copyvalue)
+        free(iter->value.data);
+      free(iter);
+      iter = next;
+    }
+  }
+  free(hash->cells);
+  free(hash);
+}
+
+void chash_clear(chash * hash) {
+  unsigned int indx;
+  chashiter * iter, * next;
+
+  /* browse the hash table */
+  for(indx = 0; indx < hash->size; indx++) {
+    iter = hash->cells[indx];
+    while (iter) {
+      next = iter->next;
+      if (hash->copykey)
+        free(iter->key.data);
+      if (hash->copyvalue)
+        free(iter->value.data);
+      free(iter);
+      iter = next;
+    }
+  }
+  memset(hash->cells, 0, hash->size * sizeof(* hash->cells));
+  hash->count = 0;
+}
+
+chashiter * chash_begin(chash * hash) {
+  chashiter * iter;
+  unsigned int indx = 0;
+  
+  iter = hash->cells[0];
+  while(!iter) {
+    indx++;
+    if (indx >= hash->size)
+      return NULL;
+    iter = hash->cells[indx];
+  }
+  return iter;
+}
+
+chashiter * chash_next(chash * hash, chashiter * iter) {
+  unsigned int indx;
+
+  if (!iter)
+    return NULL;
+
+  indx = iter->func % hash->size;
+  iter = iter->next;
+
+  while(!iter) {
+    indx++;
+    if (indx >= hash->size)
+      return NULL;
+    iter = hash->cells[indx];
+  }
+  return iter;
+}
+
+int chash_resize(chash * hash, unsigned int size)
+{
+  struct chashcell ** cells;
+  unsigned int indx, nindx;
+  chashiter * iter, * next;
+  
+  if (hash->size == size)
+    return 0;
+
+  cells = (struct chashcell **) calloc(size, sizeof(struct chashcell *));
+  if (!cells)
+    return -1;
+
+  /* browse initial hash and copy items in second hash */
+  for(indx = 0; indx < hash->size; indx++) {
+    iter = hash->cells[indx];
+    while (iter) {
+      next = iter->next;
+      nindx = iter->func % size;
+      iter->next = cells[nindx];
+      cells[nindx] = iter;
+      iter = next;
+    }
+  }
+  free(hash->cells);
+  hash->size = size;
+  hash->cells = cells;
+
+  return 0;
+}
+
+#ifdef NO_MACROS
+int chash_count(chash * hash) {
+  return hash->count;
+}
+
+int chash_size(chash * hash) {
+  return hash->size;
+}
+
+void chash_value(chashiter * iter, chashdatum * result) {
+  * result = iter->value;
+}
+
+void chash_key(chashiter * iter, chashdatum * result) {
+  * result = iter->key;
+}
+#endif