PARQUET-503: Reenable parquet 2.0 encoding implementations.

Author: Nong Li <[email protected]> Closes apache#35 from nongli/parquet-503 and squashes the following commits: cb2a4e1 [Nong Li] PARQUET-503: Reenable parquet 2.0 encoding implementations. Change-Id: Id3801ddb44164bcc63adc3ee83250d33c1d7e191
wesm · Feb 2, 2016 · 006f38e · 006f38e
1 parent 4e5002f
commit 006f38e
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Showing 5 changed files with 46 additions and 29 deletions.
diff --git a/cpp/src/parquet/encodings/delta-bit-pack-encoding.h b/cpp/src/parquet/encodings/delta-bit-pack-encoding.h
@@ -54,7 +54,7 @@ class DeltaBitPackDecoder : public Decoder<TYPE> {
   using Decoder<TYPE>::num_values_;
 
   void InitBlock() {
-    uint64_t block_size;
+    int32_t block_size;
     if (!decoder_.GetVlqInt(&block_size)) ParquetException::EofException();
     if (!decoder_.GetVlqInt(&num_mini_blocks_)) ParquetException::EofException();
     if (!decoder_.GetVlqInt(&values_current_block_)) {
@@ -104,17 +104,17 @@ class DeltaBitPackDecoder : public Decoder<TYPE> {
   }
 
   BitReader decoder_;
-  uint64_t values_current_block_;
-  uint64_t num_mini_blocks_;
+  int32_t values_current_block_;
+  int32_t num_mini_blocks_;
   uint64_t values_per_mini_block_;
   uint64_t values_current_mini_block_;
 
-  int64_t min_delta_;
+  int32_t min_delta_;
   int mini_block_idx_;
   std::vector<uint8_t> delta_bit_widths_;
   int delta_bit_width_;
 
-  int64_t last_value_;
+  int32_t last_value_;
 };
 } // namespace parquet_cpp
 

diff --git a/cpp/src/parquet/encodings/encodings.h b/cpp/src/parquet/encodings/encodings.h
@@ -105,10 +105,8 @@ class Encoder {
 
 #include "parquet/encodings/plain-encoding.h"
 #include "parquet/encodings/dictionary-encoding.h"
-
-// The encoding tools changed and these are missing the ZigZag functions
-// #include "parquet/encodings/delta-bit-pack-encoding.h"
-// #include "parquet/encodings/delta-length-byte-array-encoding.h"
-// #include "parquet/encodings/delta-byte-array-encoding.h"
+#include "parquet/encodings/delta-bit-pack-encoding.h"
+#include "parquet/encodings/delta-length-byte-array-encoding.h"
+#include "parquet/encodings/delta-byte-array-encoding.h"
 
 #endif // PARQUET_ENCODINGS_ENCODINGS_H
diff --git a/cpp/src/parquet/util/bit-stream-utils.h b/cpp/src/parquet/util/bit-stream-utils.h
@@ -69,7 +69,10 @@ class BitWriter {
   /// room.  The value is written byte aligned.
   /// For more details on vlq:
   /// en.wikipedia.org/wiki/Variable-length_quantity
-  bool PutVlqInt(int32_t v);
+  bool PutVlqInt(uint32_t v);
+
+  // Writes an int zigzag encoded.
+  bool PutZigZagVlqInt(int32_t v);
 
   /// Get a pointer to the next aligned byte and advance the underlying buffer
   /// by num_bytes.
@@ -135,17 +138,16 @@ class BitReader {
   /// the buffer.
   bool GetVlqInt(int32_t* v);
 
+  // Reads a zigzag encoded int `into` v.
+  bool GetZigZagVlqInt(int32_t* v);
+
   /// Returns the number of bytes left in the stream, not including the current
   /// byte (i.e., there may be an additional fraction of a byte).
   int bytes_left() { return max_bytes_ - (byte_offset_ + BitUtil::Ceil(bit_offset_, 8)); }
 
   /// Maximum byte length of a vlq encoded int
   static const int MAX_VLQ_BYTE_LEN = 5;
 
-  // TODO(nongli): implementations to be fixed given changes in Impala
-  // bool GetZigZagVlqInt(int64_t* v);
-  // bool PutZigZagVlqInt(int32_t v);
-
  private:
   const uint8_t* buffer_;
   int max_bytes_;

diff --git a/cpp/src/parquet/util/bit-stream-utils.inline.h b/cpp/src/parquet/util/bit-stream-utils.inline.h
@@ -75,7 +75,7 @@ inline bool BitWriter::PutAligned(T val, int num_bytes) {
   return true;
 }
 
-inline bool BitWriter::PutVlqInt(int32_t v) {
+inline bool BitWriter::PutVlqInt(uint32_t v) {
   bool result = true;
   while ((v & 0xFFFFFF80) != 0L) {
     result &= PutAligned<uint8_t>((v & 0x7F) | 0x80, 1);
@@ -152,20 +152,18 @@ inline bool BitReader::GetVlqInt(int32_t* v) {
   return true;
 }
 
-// TODO(nongli): review/test these implementations given divergence in Impala
-// functions
-
-// inline bool BitWriter::PutZigZagVlqInt(int32_t v) {
-//   uint32_t u = (v << 1) ^ (v >> 31);
-//   return PutVlqInt(u);
-// }
+inline bool BitWriter::PutZigZagVlqInt(int32_t v) {
+  uint32_t u = (v << 1) ^ (v >> 31);
+  return PutVlqInt(u);
+}
 
-// inline bool BitReader::GetZigZagVlqInt(int64_t* v) {
-//   uint64_t u;
-//   if (!GetVlqInt(&u)) return false;
-//   *reinterpret_cast<uint64_t*>(v) = (u >> 1) ^ -(u & 1);
-//   return true;
-// }
+inline bool BitReader::GetZigZagVlqInt(int32_t* v) {
+  int32_t u_signed;
+  if (!GetVlqInt(&u_signed)) return false;
+  uint32_t u = static_cast<uint32_t>(u_signed);
+  *reinterpret_cast<uint32_t*>(v) = (u >> 1) ^ -(u & 1);
+  return true;
+}
 
 } // namespace parquet_cpp
 

diff --git a/cpp/src/parquet/util/bit-util-test.cc b/cpp/src/parquet/util/bit-util-test.cc
@@ -26,6 +26,7 @@
 #include <gtest/gtest.h>
 
 #include "parquet/util/bit-util.h"
+#include "parquet/util/bit-stream-utils.inline.h"
 #include "parquet/util/cpu-info.h"
 
 namespace parquet_cpp {
@@ -161,4 +162,22 @@ TEST(BitUtil, RoundUpDown) {
   EXPECT_EQ(BitUtil::RoundDownNumi64(65), 1);
 }
 
+void TestZigZag(int32_t v) {
+  uint8_t buffer[BitReader::MAX_VLQ_BYTE_LEN];
+  BitWriter writer(buffer, sizeof(buffer));
+  BitReader reader(buffer, sizeof(buffer));
+  writer.PutZigZagVlqInt(v);
+  int32_t result;
+  EXPECT_TRUE(reader.GetZigZagVlqInt(&result));
+  EXPECT_EQ(v, result);
+}
+
+TEST(BitStreamUtil, ZigZag) {
+  TestZigZag(0);
+  TestZigZag(1);
+  TestZigZag(-1);
+  TestZigZag(std::numeric_limits<int32_t>::max());
+  TestZigZag(-std::numeric_limits<int32_t>::max());
+}
+
 } // namespace parquet_cpp