New XBT module: file

[simgrid.git] / include / xbt / str.h

diff --git a/include/xbt/str.h b/include/xbt/str.h
index ea8dcc3..2a64e95 100644 (file)
--- a/include/xbt/str.h
+++ b/include/xbt/str.h
@@ -1,6 +1,6 @@
 /* str.h - XBT string related functions.                                    */
 
-/* Copyright (c) 2007, 2008, 2009, 2010. The SimGrid Team.
+/* Copyright (c) 2007-2015. The SimGrid Team.
  * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it
@@ -10,21 +10,22 @@
 #define XBT_STR_H
 
 #include <stdarg.h>             /* va_* */
+#include <stdio.h>  /* FILE */
 #include "xbt/misc.h"
 #include "xbt/dynar.h"
 #include "xbt/dict.h"
-#include "simgrid_config.h"     /* FILE for getline */
 
 SG_BEGIN_DECL()
 
 /** @addtogroup XBT_str
  *  @brief String manipulation functions
  *
- * This module defines several string related functions. We redefine some quite classical
- * functions on the platforms were they are not nativaly defined (such as getline() or
- * asprintf()), while some other are a bit more exotic.
+ * This module defines several string related functions. Looking at the diversity of string
+ * manipulation functions that are provided, you can see that several SimGrid core developers
+ * actually like Perl.
  * @{
  */
+
 /* Trim related functions */
 XBT_PUBLIC(void) xbt_str_rtrim(char *s, const char *char_list);
 XBT_PUBLIC(void) xbt_str_ltrim(char *s, const char *char_list);
@@ -49,15 +50,90 @@ XBT_PUBLIC(char *) xbt_str_diff(const char *a, const char *b);
 
 XBT_PUBLIC(char *) xbt_str_from_file(FILE * file);
 
-XBT_INLINE XBT_PUBLIC(unsigned int) xbt_dict_hash_ext(const char *str,
-                                                      int str_len);
-XBT_INLINE XBT_PUBLIC(unsigned int) xbt_dict_hash(const char *str);
-                                                      
-/** @brief Classical alias to (char*)
- *
- * This of almost no use, beside cosmetics and the XBT datadesc parsing macro (see \ref XBT_dd_auto).
+XBT_PUBLIC(int) xbt_str_start_with(const char* str, const char* start);
+
+#define DJB2_HASH_FUNCTION
+//#define FNV_HASH_FUNCTION
+
+/**
+ * @brief Returns the hash code of a string.
  */
-typedef char *xbt_string_t;
+static XBT_INLINE unsigned int xbt_str_hash_ext(const char *str, int str_len)
+{
+
+#ifdef DJB2_HASH_FUNCTION
+  /* fast implementation of djb2 algorithm */
+  int c;
+  unsigned int hash = 5381;
+
+  while (str_len--) {
+    c = *str++;
+    hash = ((hash << 5) + hash) + c;    /* hash * 33 + c */
+  }
+# elif defined(FNV_HASH_FUNCTION)
+  unsigned int hash = 0x811c9dc5;
+  unsigned char *bp = (unsigned char *) str;    /* start of buffer */
+  unsigned char *be = bp + str_len;     /* beyond end of buffer */
+
+  while (bp < be) {
+    /* multiply by the 32 bit FNV magic prime mod 2^32 */
+    hash +=
+        (hash << 1) + (hash << 4) + (hash << 7) + (hash << 8) +
+        (hash << 24);
+
+    /* xor the bottom with the current octet */
+    hash ^= (unsigned int) *bp++;
+  }
+
+# else
+  unsigned int hash = 0;
+
+  while (str_len--) {
+    hash += (*str) * (*str);
+    str++;
+  }
+#endif
+
+  return hash;
+}
+
+/**
+ * @brief Returns the hash code of a string.
+ */
+static XBT_INLINE unsigned int xbt_str_hash(const char *str)
+{
+#ifdef DJB2_HASH_FUNCTION
+  /* fast implementation of djb2 algorithm */
+  int c;
+  unsigned int hash = 5381;
+
+  while ((c = *str++)) {
+    hash = ((hash << 5) + hash) + c;    /* hash * 33 + c */
+  }
+
+# elif defined(FNV_HASH_FUNCTION)
+  unsigned int hash = 0x811c9dc5;
+
+  while (*str) {
+    /* multiply by the 32 bit FNV magic prime mod 2^32 */
+    hash +=
+        (hash << 1) + (hash << 4) + (hash << 7) + (hash << 8) +
+        (hash << 24);
+
+    /* xor the bottom with the current byte */
+    hash ^= (unsigned int) *str++;
+  }
+
+# else
+  unsigned int hash = 0;
+
+  while (*str) {
+    hash += (*str) * (*str);
+    str++;
+  }
+#endif
+  return hash;
+}
 
 /**@}*/