encoding: Add TLV-related definitions, data structures, abstraction, and functions
Change-Id: I2dbdd5ae17f1f60cdd65b7e46e5b43b25c7f025c
diff --git a/src/encoding/block.cpp b/src/encoding/block.cpp
new file mode 100644
index 0000000..c19cee7
--- /dev/null
+++ b/src/encoding/block.cpp
@@ -0,0 +1,210 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013, Regents of the University of California
+ *
+ * BSD license, See the LICENSE file for more information
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#include <ndn-cpp/encoding/block.hpp>
+#include <ndn-cpp/encoding/tlv.hpp>
+
+namespace ndn {
+
+Block::Block()
+ : m_type(std::numeric_limits<uint32_t>::max())
+{
+}
+
+Block::Block(const ConstBufferPtr &wire,
+ uint32_t type,
+ const Buffer::const_iterator &begin, Buffer::const_iterator &end,
+ const Buffer::const_iterator &valueBegin, Buffer::const_iterator &valueEnd)
+ : m_buffer(wire)
+ , m_type(type)
+ , m_begin(begin)
+ , m_end(end)
+ , m_size(m_end - m_begin)
+ , m_value_begin(valueBegin)
+ , m_value_end(valueEnd)
+{
+}
+
+Block::Block(const ConstBufferPtr &buffer)
+ : m_buffer(buffer)
+ , m_begin(m_buffer->begin())
+ , m_end(m_buffer->end())
+ , m_size(m_end - m_begin)
+{
+ m_value_begin = m_buffer->begin();
+ m_value_end = m_buffer->end();
+
+ m_type = Tlv::readType(m_value_begin, m_value_end);
+
+ uint64_t length = Tlv::readVarNumber(m_value_begin, m_value_end);
+ if (length != (m_value_end - m_value_begin))
+ {
+ throw Tlv::Error("TLV length doesn't match buffer length");
+ }
+}
+
+Block::Block(const uint8_t *buffer, size_t maxlength)
+{
+ const uint8_t * tmp_begin = buffer;
+ const uint8_t * tmp_end = buffer + maxlength;
+
+ m_type = Tlv::readType(tmp_begin, tmp_end);
+ uint64_t length = Tlv::readVarNumber(tmp_begin, tmp_end);
+
+ if (length > (tmp_end - tmp_begin))
+ {
+ throw Tlv::Error("Not enough data in the buffer to fully parse TLV");
+ }
+
+ m_buffer = ptr_lib::make_shared<Buffer> (buffer, (tmp_begin - buffer) + length);
+
+ m_begin = m_buffer->begin();
+ m_end = m_buffer->end();
+ m_size = m_end - m_begin;
+
+ m_value_begin = m_buffer->begin() + (tmp_begin - buffer);
+ m_value_end = m_buffer->end();
+}
+
+Block::Block(const void *bufferX, size_t maxlength)
+{
+ const uint8_t * buffer = reinterpret_cast<const uint8_t*>(bufferX);
+
+ const uint8_t * tmp_begin = buffer;
+ const uint8_t * tmp_end = buffer + maxlength;
+
+ m_type = Tlv::readType(tmp_begin, tmp_end);
+ uint64_t length = Tlv::readVarNumber(tmp_begin, tmp_end);
+
+ if (length > (tmp_end - tmp_begin))
+ {
+ throw Tlv::Error("Not enough data in the buffer to fully parse TLV");
+ }
+
+ m_buffer = ptr_lib::make_shared<Buffer> (buffer, (tmp_begin - buffer) + length);
+
+ m_begin = m_buffer->begin();
+ m_end = m_buffer->end();
+ m_size = m_end - m_begin;
+
+ m_value_begin = m_buffer->begin() + (tmp_begin - buffer);
+ m_value_end = m_buffer->end();
+}
+
+Block::Block(uint32_t type)
+ : m_type(type)
+{
+}
+
+Block::Block(uint32_t type, const ConstBufferPtr &value)
+ : m_buffer(value)
+ , m_type(type)
+ , m_begin(m_buffer->end())
+ , m_end(m_buffer->end())
+ , m_value_begin(m_buffer->begin())
+ , m_value_end(m_buffer->end())
+{
+ m_size = Tlv::sizeOfVarNumber(m_type) + Tlv::sizeOfVarNumber(value_size()) + value_size();
+}
+
+Block::Block(uint32_t type, const Block &value)
+ : m_buffer(value.m_buffer)
+ , m_type(type)
+ , m_begin(m_buffer->end())
+ , m_end(m_buffer->end())
+ , m_value_begin(m_buffer->begin())
+ , m_value_end(m_buffer->end())
+{
+ m_size = Tlv::sizeOfVarNumber(m_type) + Tlv::sizeOfVarNumber(value_size()) + value_size();
+}
+
+void
+Block::parse()
+{
+ if (!m_subBlocks.empty() || value_size()==0)
+ return;
+
+ Buffer::const_iterator begin = value_begin(),
+ end = value_end();
+
+ while (begin != end)
+ {
+ Buffer::const_iterator element_begin = begin;
+
+ uint32_t type = Tlv::readType(begin, end);
+ uint64_t length = Tlv::readVarNumber(begin, end);
+
+ if (end-begin < length)
+ {
+ m_subBlocks.clear();
+ throw Tlv::Error("TLV length exceeds buffer length");
+ }
+ Buffer::const_iterator element_end = begin + length;
+
+ m_subBlocks.push_back(Block(m_buffer,
+ type,
+ element_begin, element_end,
+ begin, element_end));
+
+ begin = element_end;
+ // don't do recursive parsing, just the top level
+ }
+}
+
+void
+Block::encode()
+{
+ if (hasWire())
+ return;
+
+ OBufferStream os;
+ Tlv::writeVarNumber(os, type());
+
+ if (hasValue())
+ {
+ Tlv::writeVarNumber(os, value_size());
+ os.write(reinterpret_cast<const char*>(value()), value_size());
+ }
+ else
+ {
+ size_t valueSize = 0;
+ for (element_const_iterator i = m_subBlocks.begin(); i != m_subBlocks.end(); ++i) {
+ valueSize += i->size();
+ }
+
+ Tlv::writeVarNumber(os, valueSize);
+
+ for (element_const_iterator i = m_subBlocks.begin(); i != m_subBlocks.end(); ++i) {
+ if (i->hasWire())
+ os.write(reinterpret_cast<const char*>(i->wire()), i->size());
+ else if (i->hasValue()) {
+ Tlv::writeVarNumber(os, i->type());
+ Tlv::writeVarNumber(os, i->value_size());
+ os.write(reinterpret_cast<const char*>(i->value()), i->value_size());
+ }
+ else
+ throw Error("Underlying value buffer is empty");
+ }
+ }
+
+ // now assign correct block
+
+ m_buffer = os.buf();
+ m_begin = m_buffer->begin();
+ m_end = m_buffer->end();
+ m_size = m_end - m_begin;
+
+ m_value_begin = m_buffer->begin();
+ m_value_end = m_buffer->end();
+
+ Tlv::readType(m_value_begin, m_value_end);
+ Tlv::readVarNumber(m_value_begin, m_value_end);
+}
+
+} // namespace ndn