commit 2d0b457dcf7a98d2bcc5bdb90be6889d0248062f
author Alexander Afanasyev <alexander.afanasyev@ucla.edu> Mon Feb 24 16:02:12 2014 -0800
committer Alexander Afanasyev <alexander.afanasyev@ucla.edu> Mon Feb 24 16:02:12 2014 -0800
tree 92bb8ed4df6828377ac3c76625b28c4cd2c7f843
parent 8d7468f93edb3c2cf4065d52bc1dac99133f8e17

encoding: Ensuring minimal-length encoding for nonNegativeInteger

Change-Id: Iefb758530729f6c520c90dd36eeff2f43401f62e
refs: #1284

src/encoding/encoding-buffer.hpp

diff --git a/src/encoding/encoding-buffer.hpp b/src/encoding/encoding-buffer.hpp
index b46225b..4251fa9 100644
--- a/src/encoding/encoding-buffer.hpp
+++ b/src/encoding/encoding-buffer.hpp
@@ -166,7 +166,7 @@
 {
 public:
   EncodingImpl (size_t totalReserve = 8800,
-                  size_t reserveFromBack = 400)
+                size_t reserveFromBack = 400)
   {
   }
 
@@ -329,7 +329,7 @@
 inline size_t
 EncodingImpl<encoding::Buffer>::prependNonNegativeInteger (uint64_t varNumber)
 {
-  if (varNumber < 253) {
+  if (varNumber <= std::numeric_limits<uint8_t>::max()) {
     return prependByte (static_cast<uint8_t> (varNumber));
   }
   else if (varNumber <= std::numeric_limits<uint16_t>::max ()) {
@@ -349,7 +349,7 @@
 inline size_t
 EncodingImpl<encoding::Estimator>::prependNonNegativeInteger (uint64_t varNumber)
 {
-  if (varNumber < 253) {
+  if (varNumber <= std::numeric_limits<uint8_t>::max()) {
     return 1;
   }
   else if (varNumber <= std::numeric_limits<uint16_t>::max ()) {
@@ -448,7 +448,7 @@
 inline size_t
 EncodingImpl<encoding::Buffer>::appendNonNegativeInteger (uint64_t varNumber)
 {
-  if (varNumber < 253) {
+  if (varNumber <= std::numeric_limits<uint8_t>::max ()) {
     return appendByte (static_cast<uint8_t> (varNumber));
   }
   else if (varNumber <= std::numeric_limits<uint16_t>::max ()) {

tests/test-block.cpp

diff --git a/tests/test-block.cpp b/tests/test-block.cpp
index 7ed80fa..ea0c9b4 100644
--- a/tests/test-block.cpp
+++ b/tests/test-block.cpp
@@ -12,6 +12,115 @@
 
 BOOST_AUTO_TEST_SUITE(TestBlock)
 
+BOOST_AUTO_TEST_CASE (Basic)
+{
+  EncodingBuffer buffer;
+  EncodingEstimator estimator;
+  size_t s1, s2;
+
+  // VarNumber checks
+  
+  s1 = buffer.prependVarNumber(252);
+  s2 = estimator.prependVarNumber(252);
+  BOOST_CHECK_EQUAL(buffer.size(), 1);
+  BOOST_CHECK_EQUAL(s1, 1);
+  BOOST_CHECK_EQUAL(s2, 1);
+  buffer = EncodingBuffer();
+  
+  s1 = buffer.prependVarNumber(253);
+  s2 = estimator.prependVarNumber(253);
+  BOOST_CHECK_EQUAL(buffer.size(), 3);
+  BOOST_CHECK_EQUAL(s1, 3);
+  BOOST_CHECK_EQUAL(s2, 3);
+  buffer = EncodingBuffer();
+  
+  s1 = buffer.prependVarNumber(255);
+  s2 = estimator.prependVarNumber(255);
+  BOOST_CHECK_EQUAL(buffer.size(), 3);
+  BOOST_CHECK_EQUAL(s1, 3);
+  BOOST_CHECK_EQUAL(s2, 3);
+  buffer = EncodingBuffer();
+
+  s1 = buffer.prependVarNumber(65535);
+  s2 = estimator.prependVarNumber(65535);
+  BOOST_CHECK_EQUAL(buffer.size(), 3);
+  BOOST_CHECK_EQUAL(s1, 3);
+  BOOST_CHECK_EQUAL(s2, 3);
+  buffer = EncodingBuffer();
+
+  s1 = buffer.prependVarNumber(65536);
+  s2 = estimator.prependVarNumber(65536);
+  BOOST_CHECK_EQUAL(buffer.size(), 5);
+  BOOST_CHECK_EQUAL(s1, 5);
+  BOOST_CHECK_EQUAL(s2, 5);
+  buffer = EncodingBuffer();
+  
+  s1 = buffer.prependVarNumber(4294967295);
+  s2 = estimator.prependVarNumber(4294967295);
+  BOOST_CHECK_EQUAL(buffer.size(), 5);
+  BOOST_CHECK_EQUAL(s1, 5);
+  BOOST_CHECK_EQUAL(s2, 5);
+  buffer = EncodingBuffer();
+
+  s1 = buffer.prependVarNumber(4294967296);
+  s2 = estimator.prependVarNumber(4294967296);
+  BOOST_CHECK_EQUAL(buffer.size(), 9);
+  BOOST_CHECK_EQUAL(s1, 9);
+  BOOST_CHECK_EQUAL(s2, 9);
+  buffer = EncodingBuffer();
+
+  // nonNegativeInteger checks
+  
+  s1 = buffer.prependNonNegativeInteger(252);
+  s2 = estimator.prependNonNegativeInteger(252);
+  BOOST_CHECK_EQUAL(buffer.size(), 1);
+  BOOST_CHECK_EQUAL(s1, 1);
+  BOOST_CHECK_EQUAL(s2, 1);
+  buffer = EncodingBuffer();
+  
+  s1 = buffer.prependNonNegativeInteger(255);
+  s2 = estimator.prependNonNegativeInteger(255);
+  BOOST_CHECK_EQUAL(buffer.size(), 1);
+  BOOST_CHECK_EQUAL(s1, 1);
+  BOOST_CHECK_EQUAL(s2, 1);
+  buffer = EncodingBuffer();
+  
+  s1 = buffer.prependNonNegativeInteger(256);
+  s2 = estimator.prependNonNegativeInteger(256);
+  BOOST_CHECK_EQUAL(buffer.size(), 2);
+  BOOST_CHECK_EQUAL(s1, 2);
+  BOOST_CHECK_EQUAL(s2, 2);
+  buffer = EncodingBuffer();
+
+  s1 = buffer.prependNonNegativeInteger(65535);
+  s2 = estimator.prependNonNegativeInteger(65535);
+  BOOST_CHECK_EQUAL(buffer.size(), 2);
+  BOOST_CHECK_EQUAL(s1, 2);
+  BOOST_CHECK_EQUAL(s2, 2);
+  buffer = EncodingBuffer();
+
+  s1 = buffer.prependNonNegativeInteger(65536);
+  s2 = estimator.prependNonNegativeInteger(65536);
+  BOOST_CHECK_EQUAL(buffer.size(), 4);
+  BOOST_CHECK_EQUAL(s1, 4);
+  BOOST_CHECK_EQUAL(s2, 4);
+  buffer = EncodingBuffer();
+
+  s1 = buffer.prependNonNegativeInteger(4294967295);
+  s2 = estimator.prependNonNegativeInteger(4294967295);
+  BOOST_CHECK_EQUAL(buffer.size(), 4);
+  BOOST_CHECK_EQUAL(s1, 4);
+  BOOST_CHECK_EQUAL(s2, 4);
+  buffer = EncodingBuffer();
+
+  s1 = buffer.prependNonNegativeInteger(4294967296);
+  s2 = estimator.prependNonNegativeInteger(4294967296);
+  BOOST_CHECK_EQUAL(buffer.size(), 8);
+  BOOST_CHECK_EQUAL(s1, 8);
+  BOOST_CHECK_EQUAL(s2, 8);
+  buffer = EncodingBuffer();
+}
+
 BOOST_AUTO_TEST_CASE (EncodingBufferToBlock)
 {
   uint8_t value[4];