[svn] commit: r180 - in /experiments/jelte-configuration: data.cc data.h

[BIND 10 source code commits]

Author: mgraff
Date: Thu Oct 29 21:51:14 2009
New Revision: 180

Log:
from_wire() works

Modified:
    experiments/jelte-configuration/data.cc
    experiments/jelte-configuration/data.h

Modified: experiments/jelte-configuration/data.cc
==============================================================================
--- experiments/jelte-configuration/data.cc (original)
+++ experiments/jelte-configuration/data.cc Thu Oct 29 21:51:14 2009
@@ -506,6 +506,156 @@
 }
 
 //
+// Decode from wire format.
+//
+
+ElementPtr decode_element(std::stringstream& in, int& in_length);
+
+static unsigned char
+get_byte(std::stringstream& in)
+{
+    int c = in.get();
+    if (c == EOF) {
+        throw DecodeError("End of data while decoding wire format message");
+    }
+
+    return c;
+}
+
+std::string
+decode_tag(std::stringstream& in, int& item_length)
+{
+    char buf[256];
+
+    int len = get_byte(in);
+    item_length--;
+
+    in.read(buf, len);
+    if (in.fail()) {
+        throw DecodeError();
+    }
+    buf[len] = 0;
+    item_length -= len;
+
+    return std::string(buf);
+}
+
+ElementPtr
+decode_data(std::stringstream& in, int& item_length)
+{
+    char *buf = new char[item_length + 1];
+
+    in.read(buf, item_length);
+    if (in.fail()) {
+        throw DecodeError();
+    }
+    buf[item_length] = 0;
+    item_length -= item_length;
+
+    std::string s = std::string(buf);
+    delete [] buf;
+    return Element::create(s);
+}
+
+ElementPtr
+decode_hash(std::stringstream& in, int& item_length)
+{
+    std::map<std::string, ElementPtr> m;
+    std::pair<std::string, ElementPtr> p;
+
+    while (item_length > 0) {
+        p.first = decode_tag(in, item_length);
+        p.second = decode_element(in, item_length);
+        m.insert(p);
+    }
+
+    return Element::create(m);
+}
+
+ElementPtr
+decode_list(std::stringstream& in, int& item_length)
+{
+    std::vector<ElementPtr> v;
+
+    while (item_length > 0) {
+        v.push_back(decode_element(in, item_length));
+    }
+    return Element::create(v);
+}
+
+ElementPtr
+decode_null(std::stringstream& in, int& item_length)
+{
+    return Element::create("NULL");
+}
+
+ElementPtr
+decode_element(std::stringstream& in, int& in_length)
+{
+    ElementPtr element;
+
+    unsigned char type_and_length = get_byte(in);
+    unsigned char type = type_and_length & ITEM_MASK;
+    unsigned char lenbytes = type_and_length & ITEM_LENGTH_MASK;
+    in_length--;
+
+    int item_length = 0;
+    switch (lenbytes) {
+    case ITEM_LENGTH_32:
+        item_length |= get_byte(in);
+        item_length <<= 8;
+        item_length |= get_byte(in);
+        item_length <<= 8;
+        in_length -= 2;  // only 2 here, we will get more later
+    case ITEM_LENGTH_16:
+        item_length |= get_byte(in);
+        item_length <<= 8;
+        in_length--;  // only 1 here
+    case ITEM_LENGTH_8:
+        item_length |= get_byte(in);
+        in_length--;
+    }
+
+    in_length -= item_length;
+
+    switch (type) {
+    case ITEM_DATA:
+        element = decode_data(in, item_length);
+        break;
+    case ITEM_HASH:
+        element = decode_hash(in, item_length);
+        break;
+    case ITEM_LIST:
+        element = decode_list(in, item_length);
+        break;
+    case ITEM_NULL:
+        element = decode_null(in, item_length);
+        break;
+    }
+
+    return (element);
+}
+
+ElementPtr
+Element::from_wire(std::stringstream& in, int length)
+{
+    //
+    // Check protocol version
+    //
+    for (int i = 0 ; i < 4 ; i++) {
+        unsigned char version_byte = get_byte(in);
+        if (PROTOCOL_VERSION[i] != version_byte) {
+            throw DecodeError("Protocol version incorrect");
+        }
+    }
+    length -= 4;
+
+    ElementPtr element;
+    element = decode_hash(in, length);
+    return (element);
+}
+
+//
 // Encode into wire format.
 //
 
@@ -767,10 +917,8 @@
     ss_skan << e_skan->to_wire(1);
     hexdump(std::string(ss_skan.str()));
 
-    int counter = 100000;
-    while (counter--) {
-        (void)e_skan->to_wire(1);
-    }
+    ElementPtr decoded = Element::from_wire(ss_skan, ss_skan.str().length());
+    cout << decoded << endl;
 
     return 0;
 }

Modified: experiments/jelte-configuration/data.h
==============================================================================
--- experiments/jelte-configuration/data.h (original)
+++ experiments/jelte-configuration/data.h Thu Oct 29 21:51:14 2009
@@ -13,8 +13,17 @@
     // todo: include types and called function in the exception
     class TypeError : public std::exception {
     public:
-        TypeError(std::string m="Attempt to use function on wrong Element type") : msg(m) {}
+        TypeError(std::string m = "Attempt to use function on wrong Element type") : msg(m) {}
         ~TypeError() throw() {}
+        const char* what() const throw() { return msg.c_str(); }
+    private:
+        std::string msg;
+    };
+
+    class DecodeError : public std::exception {
+    public:
+        DecodeError(std::string m = "Wire-format data is invalid") : msg(m) {}
+        ~DecodeError() throw() {}
         const char* what() const throw() { return msg.c_str(); }
     private:
         std::string msg;
@@ -121,6 +130,8 @@
         // the memory could not be allocated
         static ElementPtr create_from_string(std::stringstream &in);
         //static ElementPtr create_from_xml(std::stringstream &in);
+
+        static ElementPtr from_wire(std::stringstream &in, int length);
     };
 
     class IntElement : public Element {
@@ -203,6 +214,7 @@
         void set(const std::string& s, ElementPtr p) { m[s] = p; };
         std::string str();
         std::string str_xml(size_t prefix = 0);
+
         std::string to_wire(int omit_length = 0);
         
         //