diff packages/language/c/libc/stdlib/current/src/bsearch.cxx @ 115:6ed91473a1cd ecos-sw-2000-08-21

Merge from eCos master repository on 2000-08-21-22:40:54-BST
author jlarmour
date Fri, 25 Aug 2000 17:32:38 +0000
parents
children e0c0827131d1
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+++ b/packages/language/c/libc/stdlib/current/src/bsearch.cxx
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+//===========================================================================
+//
+//      bsearch.cxx
+//
+//      ANSI standard binary search function defined in section 7.10.5.1
+//      of the standard
+//
+//===========================================================================
+//####COPYRIGHTBEGIN####
+//                                                                          
+// -------------------------------------------                              
+// The contents of this file are subject to the Red Hat eCos Public License 
+// Version 1.1 (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.redhat.com/                                                   
+//                                                                          
+// Software distributed under the License is distributed on an "AS IS"      
+// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the 
+// License for the specific language governing rights and limitations under 
+// the License.                                                             
+//                                                                          
+// The Original Code is eCos - Embedded Configurable Operating System,      
+// released September 30, 1998.                                             
+//                                                                          
+// The Initial Developer of the Original Code is Red Hat.                   
+// Portions created by Red Hat are                                          
+// Copyright (C) 1998, 1999, 2000 Red Hat, Inc.                             
+// All Rights Reserved.                                                     
+// -------------------------------------------                              
+//                                                                          
+//####COPYRIGHTEND####
+//===========================================================================
+//#####DESCRIPTIONBEGIN####
+//
+// Author(s):    jlarmour
+// Contributors: 
+// Date:         2000-04-30
+// Purpose:     
+// Description: 
+// Usage:       
+//
+//####DESCRIPTIONEND####
+//
+//===========================================================================
+
+// CONFIGURATION
+
+#include <pkgconf/libc_stdlib.h>   // Configuration header
+
+// INCLUDES
+
+#include <cyg/infra/cyg_type.h>    // Common type definitions and support
+#include <cyg/infra/cyg_trac.h>    // Tracing support
+#include <cyg/infra/cyg_ass.h>     // Assertion support
+#include <stdlib.h>                // Header for all stdlib functions
+                                   // (like this one)
+
+// TRACING
+
+# if defined(CYGDBG_USE_TRACING) && \
+     defined(CYGNUM_LIBC_BSEARCH_TRACE_LEVEL)
+static int bsearch_trace = CYGNUM_LIBC_BSEARCH_TRACE_LEVEL;
+#  define TL1 (0 < bsearch_trace)
+# else
+#  define TL1 (0)
+# endif
+
+
+// FUNCTIONS
+
+externC void *
+bsearch( const void *key, const void *base, size_t nmemb, size_t size,
+         __bsearch_comparison_fn_t compar )
+{
+    CYG_REPORT_FUNCNAMETYPE( "bsearch", "returning %08x" );
+
+    CYG_REPORT_FUNCARG5( "key=%08x, base=%08x, nmemb=%d, size=%d, "
+                         "compar=%08x", key, base, nmemb, size, compar );
+
+    CYG_CHECK_DATA_PTR( key, "key is not a valid pointer!" );
+    CYG_CHECK_DATA_PTR( base, "base is not a valid pointer!" );
+    CYG_CHECK_FUNC_PTR( compar, "compar is not a valid function pointer!" );
+
+    CYG_ADDRESS current;
+    size_t lower = 0;
+    size_t upper = nmemb;
+    size_t index;
+    int result;
+    
+    if (nmemb == 0 || size == 0)
+    {
+        CYG_TRACE2( TL1, "Warning! either nmemb (%d) or size (%d) is 0",
+                    nmemb, size );
+        CYG_REPORT_RETVAL( NULL );
+        return NULL;
+    } // if
+    
+    while (lower < upper)
+    {
+        index = (lower + upper) / 2;
+        current = (CYG_ADDRESS) (((char *) base) + (index * size));
+        
+        CYG_TRACE2( TL1, "About to call comparison function with "
+                    "key=%08x, current=%08x", key, current );
+        result = compar (key, (void *) current);
+        CYG_TRACE1( TL1, "Comparison function returned %d", result );
+        
+        if (result < 0)
+            upper = index;
+        else if (result > 0)
+            lower = index + 1;
+        else
+        {
+            CYG_REPORT_RETVAL( current );
+            return (void *)current;
+        } // else
+    } // while
+    
+    CYG_REPORT_RETVAL( NULL );
+    return NULL;
+} // bsearch()
+
+// EOF bsearch.cxx