MDEV-4425 REGEXP enhancements

pcre/pcre_stringpiece.h

@@ -0,0 +1,179 @@
+// Copyright (c) 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * 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.
+//     * Neither the name of Google Inc. 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 COPYRIGHT HOLDERS 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 COPYRIGHT
+// OWNER 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.
+//
+// Author: Sanjay Ghemawat
+//
+// A string like object that points into another piece of memory.
+// Useful for providing an interface that allows clients to easily
+// pass in either a "const char*" or a "string".
+//
+// Arghh!  I wish C++ literals were automatically of type "string".
+
+#ifndef _PCRE_STRINGPIECE_H
+#define _PCRE_STRINGPIECE_H
+
+#include <cstring>
+#include <string>
+#include <iosfwd>    // for ostream forward-declaration
+
+#if 0
+#define HAVE_TYPE_TRAITS
+#include <type_traits.h>
+#elif 0
+#define HAVE_TYPE_TRAITS
+#include <bits/type_traits.h>
+#endif
+
+#include <pcre.h>
+
+using std::memcmp;
+using std::strlen;
+using std::string;
+
+namespace pcrecpp {
+
+class PCRECPP_EXP_DEFN StringPiece {
+ private:
+  const char*   ptr_;
+  int           length_;
+
+ public:
+  // We provide non-explicit singleton constructors so users can pass
+  // in a "const char*" or a "string" wherever a "StringPiece" is
+  // expected.
+  StringPiece()
+    : ptr_(NULL), length_(0) { }
+  StringPiece(const char* str)
+    : ptr_(str), length_(static_cast<int>(strlen(ptr_))) { }
+  StringPiece(const unsigned char* str)
+    : ptr_(reinterpret_cast<const char*>(str)),
+      length_(static_cast<int>(strlen(ptr_))) { }
+  StringPiece(const string& str)
+    : ptr_(str.data()), length_(static_cast<int>(str.size())) { }
+  StringPiece(const char* offset, int len)
+    : ptr_(offset), length_(len) { }
+
+  // data() may return a pointer to a buffer with embedded NULs, and the
+  // returned buffer may or may not be null terminated.  Therefore it is
+  // typically a mistake to pass data() to a routine that expects a NUL
+  // terminated string.  Use "as_string().c_str()" if you really need to do
+  // this.  Or better yet, change your routine so it does not rely on NUL
+  // termination.
+  const char* data() const { return ptr_; }
+  int size() const { return length_; }
+  bool empty() const { return length_ == 0; }
+
+  void clear() { ptr_ = NULL; length_ = 0; }
+  void set(const char* buffer, int len) { ptr_ = buffer; length_ = len; }
+  void set(const char* str) {
+    ptr_ = str;
+    length_ = static_cast<int>(strlen(str));
+  }
+  void set(const void* buffer, int len) {
+    ptr_ = reinterpret_cast<const char*>(buffer);
+    length_ = len;
+  }
+
+  char operator[](int i) const { return ptr_[i]; }
+
+  void remove_prefix(int n) {
+    ptr_ += n;
+    length_ -= n;
+  }
+
+  void remove_suffix(int n) {
+    length_ -= n;
+  }
+
+  bool operator==(const StringPiece& x) const {
+    return ((length_ == x.length_) &&
+            (memcmp(ptr_, x.ptr_, length_) == 0));
+  }
+  bool operator!=(const StringPiece& x) const {
+    return !(*this == x);
+  }
+
+#define STRINGPIECE_BINARY_PREDICATE(cmp,auxcmp)                             \
+  bool operator cmp (const StringPiece& x) const {                           \
+    int r = memcmp(ptr_, x.ptr_, length_ < x.length_ ? length_ : x.length_); \
+    return ((r auxcmp 0) || ((r == 0) && (length_ cmp x.length_)));          \
+  }
+  STRINGPIECE_BINARY_PREDICATE(<,  <);
+  STRINGPIECE_BINARY_PREDICATE(<=, <);
+  STRINGPIECE_BINARY_PREDICATE(>=, >);
+  STRINGPIECE_BINARY_PREDICATE(>,  >);
+#undef STRINGPIECE_BINARY_PREDICATE
+
+  int compare(const StringPiece& x) const {
+    int r = memcmp(ptr_, x.ptr_, length_ < x.length_ ? length_ : x.length_);
+    if (r == 0) {
+      if (length_ < x.length_) r = -1;
+      else if (length_ > x.length_) r = +1;
+    }
+    return r;
+  }
+
+  string as_string() const {
+    return string(data(), size());
+  }
+
+  void CopyToString(string* target) const {
+    target->assign(ptr_, length_);
+  }
+
+  // Does "this" start with "x"
+  bool starts_with(const StringPiece& x) const {
+    return ((length_ >= x.length_) && (memcmp(ptr_, x.ptr_, x.length_) == 0));
+  }
+};
+
+}   // namespace pcrecpp
+
+// ------------------------------------------------------------------
+// Functions used to create STL containers that use StringPiece
+//  Remember that a StringPiece's lifetime had better be less than
+//  that of the underlying string or char*.  If it is not, then you
+//  cannot safely store a StringPiece into an STL container
+// ------------------------------------------------------------------
+
+#ifdef HAVE_TYPE_TRAITS
+// This makes vector<StringPiece> really fast for some STL implementations
+template<> struct __type_traits<pcrecpp::StringPiece> {
+  typedef __true_type    has_trivial_default_constructor;
+  typedef __true_type    has_trivial_copy_constructor;
+  typedef __true_type    has_trivial_assignment_operator;
+  typedef __true_type    has_trivial_destructor;
+  typedef __true_type    is_POD_type;
+};
+#endif
+
+// allow StringPiece to be logged
+std::ostream& operator<<(std::ostream& o, const pcrecpp::StringPiece& piece);
+
+#endif /* _PCRE_STRINGPIECE_H */