src/third_party/domain_registry_provider/src/domain_registry/private/string_util.h

/*
 * Copyright 2011 Google Inc.
 *
 * Licensed 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.
 */

#ifndef DOMAIN_REGISTRY_PRIVATE_STRING_UTIL_H_
#define DOMAIN_REGISTRY_PRIVATE_STRING_UTIL_H_

#include <stdio.h>
#include <string.h>

#include "domain_registry/private/assert.h"

static const char kUpperLowerDistance = 'A' - 'a';

#if _WINDOWS
#define __inline__ __inline
#endif

static __inline__ int IsWildcardComponent(const char* component) {
  if (component[0] == '*') {
    return 1;
  }
  return 0;
}

static __inline__ int IsExceptionComponent(const char* component) {
  if (component[0] == '!') {
    return 1;
  }
  return 0;
}

static __inline__ int IsInvalidComponent(const char* component) {
  if (component == NULL ||
      component[0] == 0 ||
      IsExceptionComponent(component) ||
      IsWildcardComponent(component)) {
    return 1;
  }
  return 0;
}

static __inline__ void ReplaceChar(char* value, char old, char newval) {
  while ((value = strchr(value, old)) != NULL) {
    *value = newval;
    ++value;
  }
}

static __inline__ void ToLowerASCII(char* buf, const char* end) {
  for (; buf < end; ++buf) {
    char c = *buf;
    if (c >= 'A' && c <= 'Z') {
      *buf = c - kUpperLowerDistance;
    }
  }
}

static __inline__ int HostnamePartCmp(const char *a, const char *b) {
  /*
   * Optimization: do not invoke strcmp() unless the first characters
   * in each string match. Since we are performing a binary search, we
   * expect most invocations to strcmp to not have matching arguments,
   * and thus not invoke strcmp. This reduces overall runtime by 5-10%
   * on a Linux laptop running a -O2 optimized build.
   */
  int ret = *(unsigned char *)a - *(unsigned char *)b;
  /*
   * NOTE: we could invoke strcmp on a+1,b+1 if we are
   * certain that neither a nor b are the empty string. For now we
   * take the more conservative approach.
   */
  if (ret == 0) return strcmp(a, b);
  return ret;
}

#endif  /* DOMAIN_REGISTRY_PRIVATE_STRING_UTIL_H_ */