Diff: mbed-client/source/m2mstring.cpp

Revision:

11:cada08fc8a70

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-client/source/m2mstring.cpp	Thu Jun 09 17:08:36 2016 +0000
@@ -0,0 +1,366 @@
+/*
+ * Copyright (c) 2015 ARM Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ * 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.
+ */
+#include "mbed-client/m2mstring.h"
+#include <string.h> // strlen
+#include <stdlib.h> // malloc, realloc
+#include <assert.h>
+#include <algorithm> // min
+
+namespace m2m {
+
+  const String::size_type String::npos = static_cast<size_t>(-1);
+
+  /*
+   * Like the 'new' operator, we want to guarantee that we NEVER
+   * return NULL. Loop until there is free memory.
+   *
+   */
+  static char* malloc_never_null(const size_t b)
+  {
+      char *p;
+
+      do {
+          p = static_cast<char*>(malloc(b));
+      } while ( p == NULL );
+
+      return p;
+  }
+
+  /**
+   * Allocates memory for the copy the string at the same time sets "this->allocated".
+   * @param s
+   * @return
+   */
+  char*
+  String::strdup_never_null(const char* s)
+  {
+      const size_t len = strlen(s)+1;
+      char *p2 = malloc_never_null(len);
+      memcpy(p2, s, len);
+      allocated_=len;
+      size_=len-1;
+      return p2;
+  }
+
+  String::String()
+  : p( strdup_never_null("") )
+  {
+    _return_value = '\0';
+  }
+
+  String::~String()
+  {
+      free(p);
+      p = 0;
+  }
+
+  String::String(const String& s)
+    : p(0)
+  {
+    if( &s != NULL ){
+        p = malloc_never_null( s.size_ + 1 );  // copy only used part
+        allocated_ = s.size_ + 1;
+        size_      = s.size_;
+        memcpy(p, s.p, size_ + 1);
+    }
+    _return_value = '\0';
+  }
+
+  String::String(const char* s)
+  : p(strdup_never_null(s))
+  {
+      _return_value = '\0';
+  }
+
+  String& String::operator=(const char* s)
+  {
+      if ( p != s ) {
+            // s could point into our own string, so we have to allocate a new string
+            const size_t len = strlen(s);
+            char* copy = (char*) malloc( len + 1);
+            memmove(copy, s, len+1); // trailing 0
+            free( p );
+            p = copy;
+            size_ = len;
+            allocated_ = len+1;
+      }
+
+      return *this;
+  }
+
+  String& String::operator=(const String& s)
+  {
+      return operator=(s.p);
+  }
+
+  String& String::operator+=(const String& s)
+  {
+    if (s.size_ > 0){
+      this->reserve(size_ + s.size_);
+      memmove(p+size_, s.p, s.size_+1); // trailing 0
+      size_ += s.size_;
+    }
+    return *this;
+  }
+
+  // since p and s may overlap, we have to copy our own string first
+  String& String::operator+=(const char* s)
+  {
+      const size_type lens = strlen(s);
+      if (lens > 0){
+        if (size_ + lens + 1 <= allocated_) {
+          memmove(p+size_, s, lens+1); // trailing 0
+          size_ += lens;
+        } else {
+          String s2( *this );  // copy own data
+          s2.reserve(size_ + lens);
+          memmove(s2.p+size_, s, lens+1); // trailing 0
+          s2.size_ = size_ + lens;
+          this->swap( s2 );
+        }
+      }
+      return *this;
+  }
+
+  String& String::operator+=(const char c)
+  {
+      push_back(c);
+      return *this;
+  }
+
+
+  void String::push_back(const char c) {
+
+    if (size_ == allocated_ - 1) {
+      size_t more =  (allocated_* 3) / 2; // factor 1.5
+      if ( more < 4 ) more = 4;
+      reserve( size_ + more );
+    }
+
+    p[size_] = c;
+    size_++;
+    p[size_] = 0;
+  }
+
+  bool String::operator==(const char* s) const
+  {
+      if( s == NULL ){
+          if( p == NULL ){
+              return true;
+          }
+          return false;
+      }
+      bool ret = strcmp(p, s);
+      return !ret;
+  }
+
+  bool String::operator==(const String& s) const
+  {
+      bool ret = strcmp(p, s.p);
+      return !ret;
+  }
+
+  void String::clear()
+  {
+      size_ = 0;
+      p[0]  = 0;
+  }
+
+//  String operator+(const String& lhs, const String& rhs)
+//  {
+//      return String(lhs) += rhs;
+//  }
+
+  String String::substr(const size_type pos, size_type length) const
+  {
+      String s;
+      const size_type len = size_;
+
+      if ( pos <= len ) {
+
+      size_type remain = len - pos;
+
+      if ( length > remain )
+          length = remain;
+
+      s.reserve( length );
+
+      memcpy(s.p, p + pos, length);
+      s.p[length] = '\0';
+      s.size_ = length;
+      }
+      return s;
+  }
+
+
+  // checked access, accessing the NUL at end is allowed
+  char& String::at(const size_type i)
+  {
+      if ( i <= strlen(p) ) {
+        _return_value = p[i];
+      } else {
+      _return_value = '\0';
+      }
+      return _return_value;
+  }
+
+  char String::at(const size_type i) const
+  {
+      if ( i <= strlen(p) ) {
+        return p[i];
+      } else {
+         return '\0';
+      }
+  }
+
+  String& String::erase(size_type pos, size_type len)
+  {
+    if (len > 0) {
+
+      if ( pos < size_ ) { // user must not remove trailing 0
+
+          size_type s2 = size_;
+          size_type remain = s2 - pos - len;
+
+          if (remain > 0) {
+            // erase by overwriting
+            memmove(p + pos, p + pos + len, remain);
+          }
+
+          //if ( remain < 0 ) remain = 0;
+
+          // remove unused space
+          this->resize( pos+remain );
+
+        }
+    }
+    return *this;
+  }
+
+  String& String::append( const char* str, size_type n) {
+    if (str && n > 0) {
+      size_t lens = strlen(str);
+      if (n > lens)
+        n = lens;
+      size_t newlen = size_ + n;
+      this->reserve( newlen );
+      memmove(p+size_, str, n); // p and s.p MAY overlap
+      p[newlen] = 0; // add NUL termination
+      size_ = newlen;
+    }
+    return *this;
+  }
+
+  int
+  String::compare( size_type pos, size_type len, const String& str ) const {
+    int r = -1;
+    if (pos <= size_) {
+        if ( len > size_ - pos)
+          len = size_ - pos; // limit len to available length
+
+        const size_type osize = str.size();
+        const size_type len2   = std::min(len, osize);
+        r = strncmp( p + pos, str.p, len2);
+        if (r==0) // equal so far, now compare sizes
+            r = len < osize ? -1 : ( len == osize ? 0 : +1 );
+    }
+    return r;
+  }
+
+  int
+  String::compare( size_type pos, size_type len, const char* str ) const {
+      int r = -1;
+      if (pos <= size_) {
+
+        if ( len > size_ - pos)
+          len = size_ - pos; // limit len to available length
+
+        const size_type osize = strlen(str);
+        const size_type len2   = std::min(len, osize);
+        r = strncmp( p + pos, str, len2);
+        if (r==0) // equal so far, now compare sizes
+            r = len < osize ? -1 : ( len == osize ? 0 : +1 );
+    }
+    return r;
+  }
+
+ int
+ String::find_last_of(char c) const {
+    int r = -1;
+    char *v;
+    v = strrchr(p,c);
+    if (v != NULL){
+        r = 0;
+        char* i = p;
+        while (v != i){
+            i++;
+            r++;
+        }
+    }
+    return r;
+ }
+
+  void
+  String::new_realloc( size_type n) {
+    if (n > 0 ) {
+      char* pnew = static_cast<char*>(realloc(p, n)); // could return NULL
+      if (pnew)
+        p = pnew;
+    }
+   }
+
+
+  void
+  String::reserve( const size_type n) {
+    if (n >= allocated_ ) {
+      this->new_realloc(n + 1);
+      allocated_ = n + 1;
+    }
+  }
+
+  void
+  String::resize( const size_type n) {
+    this->resize( n, 0 );
+  }
+
+  void
+  String::resize( const size_type n, const char c) {
+    if (n < size_ ) {
+      p[n] = 0;
+      size_ = n;
+    }
+    else if (n >  size_ ) {
+      this->reserve( n );
+      for (size_type i=size_; i < n; ++i )
+        p[i] = c;
+      p[n] = 0;
+      size_ = n;
+    }
+  }
+
+  void String::swap( String& s ) {
+    std::swap( allocated_, s.allocated_ );
+    std::swap( size_,      s.size_      );
+    std::swap( p,          s.p          );
+  }
+
+
+  // Comparison
+  bool operator<( const String& s1, const String& s2 ) {
+    return strcmp( s1.c_str(), s2.c_str() ) < 0;
+  }
+
+} // namespace