[Courgette] Make BSDiff search() use lexicographical_compare().

courgette/third_party/bsdiff/qsufsort.h

 // Copyright 2003, 2004 Colin Percival
 // All rights reserved
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted providing 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
@@ skipping 30 matching lines @@
 //              http://www.larsson.dogma.net/qsufsort.c
 //                --Samuel Huang <huangs@chromium.org>
 
 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COURGETTE_THIRD_PARTY_BSDIFF_QSUFSORT_H_
 #define COURGETTE_THIRD_PARTY_BSDIFF_QSUFSORT_H_
 
-#include <algorithm>
-#include <cstring>
-
 namespace courgette {
 namespace qsuf {
 
 // ------------------------------------------------------------------------
 //
 // The following code is taken verbatim from 'bsdiff.c'. Please keep all the
 // code formatting and variable names.  The changes from the original are:
 // (1) replacing tabs with spaces,
 // (2) indentation and spacing,
 // (3) using 'const',
@@ skipping 149 matching lines @@
       };
     };
     if (len)
       I[i - len] = -len;
   };
 
   for (i = 0; i < oldsize + 1; i++)
     I[V[i]] = i;
 }
 
-static int matchlen(const unsigned char* old,
-                    int oldsize,
-                    const unsigned char* newbuf,
-                    int newsize) {
-  int i;
-
-  for (i = 0; (i < oldsize) && (i < newsize); i++)
-    if (old[i] != newbuf[i])
-      break;
-
-  return i;
-}
-
-template <class T>
-static int search(T I,
-                  const unsigned char* old,
-                  int oldsize,
-                  const unsigned char* newbuf,
-                  int newsize,
-                  int* pos) {
-  int lo = 0;
-  int hi = oldsize;
-  while (hi - lo >= 2) {
-    int mid = (lo + hi) / 2;
-    if (memcmp(old + I[mid], newbuf, std::min(oldsize - I[mid], newsize)) < 0) {
-      lo = mid;
-    } else {
-      hi = mid;
-    }
-  }
-
-  int x = matchlen(old + I[lo], oldsize - I[lo], newbuf, newsize);
-  int y = matchlen(old + I[hi], oldsize - I[hi], newbuf, newsize);
-  if (x > y) {
-    *pos = I[lo];
-    return x;
-  }
-  *pos = I[hi];
-  return y;
-}
-
 //  End of 'verbatim' code.
 // ------------------------------------------------------------------------
 
 }  // namespace qsuf
 }  // namespace courgette
+
 #endif  // COURGETTE_THIRD_PARTY_BSDIFF_QSUFSORT_H_