1 files changed, 124 insertions, 0 deletions
diff --git a/decoder/fdict.cc b/decoder/fdict.cc
index 8218a5d3..7e1b0e1f 100644
--- a/decoder/fdict.cc
+++ b/decoder/fdict.cc
@@ -1,5 +1,129 @@
 #include "fdict.h"
 
+#include <string>
+
+using namespace std;
+
 Dict FD::dict_;
 bool FD::frozen_ = false;
 
+static int HexPairValue(const char * code) {
+  int value = 0;
+  const char * pch = code;
+  for (;;) {
+    int digit = *pch++;
+    if (digit >= '0' && digit <= '9') {
+      value += digit - '0';
+    }
+    else if (digit >= 'A' && digit <= 'F') {
+      value += digit - 'A' + 10;
+    }
+    else if (digit >= 'a' && digit <= 'f') {
+      value += digit - 'a' + 10;
+    }
+    else {
+      return -1;
+    }
+    if (pch == code + 2)
+      return value;
+    value <<= 4;
+  }
+}
+
+int UrlDecode(const char *source, char *dest)
+{
+  char * start = dest;
+
+  while (*source) {
+    switch (*source) {
+    case '+':
+      *(dest++) = ' ';
+      break;
+    case '%':
+      if (source[1] && source[2]) {
+        int value = HexPairValue(source + 1);
+        if (value >= 0) {
+          *(dest++) = value;
+          source += 2;
+        }
+        else {
+          *dest++ = '?';
+        }
+      }
+      else {
+        *dest++ = '?';
+      }
+      break;
+    default:
+      *dest++ = *source;
+    }
+    source++;
+  }
+  
+  *dest = 0;
+  return dest - start;
+}  
+
+int UrlEncode(const char *source, char *dest, unsigned max) {
+  static const char *digits = "0123456789ABCDEF";
+  unsigned char ch;
+  unsigned len = 0;
+  char *start = dest;
+
+  while (len < max - 4 && *source)
+  {
+    ch = (unsigned char)*source;
+    if (*source == ' ') {
+      *dest++ = '+';
+    }
+    else if (strchr("=:;,_| %", ch)) {
+      *dest++ = '%';
+      *dest++ = digits[(ch >> 4) & 0x0F];
+      *dest++ = digits[       ch & 0x0F];
+    }
+    else {
+      *dest++ = *source;
+    }  
+    source++;
+  }
+  *dest = 0;
+  return start - dest;
+}
+
+std::string UrlDecodeString(const std::string & encoded) {
+  const char * sz_encoded = encoded.c_str();
+  size_t needed_length = encoded.length();
+  for (const char * pch = sz_encoded; *pch; pch++) {
+    if (*pch == '%')
+      needed_length += 2;
+  }
+  needed_length += 10;
+  char stackalloc[64];
+  char * buf = needed_length > sizeof(stackalloc)/sizeof(*stackalloc) ?
+    (char *)malloc(needed_length) : stackalloc;
+  UrlDecode(encoded.c_str(), buf);
+  std::string result(buf);
+  if (buf != stackalloc) {
+    free(buf);
+  }
+  return result;
+}
+
+std::string UrlEncodeString(const std::string & decoded) {
+  const char * sz_decoded = decoded.c_str();
+  size_t needed_length = decoded.length() * 3 + 3;
+  char stackalloc[64];
+  char * buf = needed_length > sizeof(stackalloc)/sizeof(*stackalloc) ?
+    (char *)malloc(needed_length) : stackalloc;
+  UrlEncode(decoded.c_str(), buf, needed_length);
+  std::string result(buf);
+  if (buf != stackalloc) {
+    free(buf);
+  }
+  return result;
+}
+
+string FD::Escape(const string& s) {
+  return UrlEncodeString(s);
+}
+