Add postscript path

This patch adds the additional functions required to make postscript
printing functional. The most significant additions are are two added
compression functions and a new API for setting the postscript level.

Not currently called from Chromium, Chromium patch to come.

BUG=

Review-Url: https://codereview.chromium.org/2612243005

3 files changed, 544 insertions, 2 deletions

diff --git a/core/fxcodec/codec/fx_codec.cpp b/core/fxcodec/codec/fx_codec.cpp
index 6b6c723388..23171cf3ea 100644
--- a/core/fxcodec/codec/fx_codec.cpp
+++ b/core/fxcodec/codec/fx_codec.cpp
@@ -6,6 +6,7 @@
 
 #include "core/fxcodec/fx_codec.h"
 
+#include <algorithm>
 #include <cmath>
 #include <memory>
 #include <utility>
@@ -101,14 +102,151 @@ bool CCodec_BasicModule::RunLengthEncode(const uint8_t* src_buf,
                                          uint32_t src_size,
                                          uint8_t** dest_buf,
                                          uint32_t* dest_size) {
-  return false;
+  // Check inputs
+  if (!src_buf || !dest_buf || !dest_size || src_size == 0)
+    return false;
+
+  // Edge case
+  if (src_size == 1) {
+    *dest_buf = FX_Alloc(uint8_t, 3);
+    (*dest_buf)[0] = 0;
+    (*dest_buf)[1] = src_buf[0];
+    (*dest_buf)[2] = 128;
+    *dest_size = 3;
+    return true;
+  }
+
+  // Worst case: 1 nonmatch, 2 match, 1 nonmatch, 2 match, etc. This becomes
+  // 4 output chars for every 3 input, plus up to 4 more for the 1-2 chars
+  // rounded off plus the terminating character.
+  uint32_t est_size = 4 * ((src_size + 2) / 3) + 1;
+  *dest_buf = FX_Alloc(uint8_t, est_size);
+
+  // Set up pointers.
+  uint8_t* out = *dest_buf;
+  uint32_t run_start = 0;
+  uint32_t run_end = 1;
+  uint8_t x = src_buf[run_start];
+  uint8_t y = src_buf[run_end];
+  while (run_end < src_size) {
+    uint32_t max_len = std::min((uint32_t)128, src_size - run_start);
+    while (x == y && (run_end - run_start < max_len - 1))
+      y = src_buf[++run_end];
+
+    // Reached end with matched run. Update variables to expected values.
+    if (x == y) {
+      run_end++;
+      if (run_end < src_size)
+        y = src_buf[run_end];
+    }
+    if (run_end - run_start > 1) {  // Matched run but not at end of input.
+      out[0] = 257 - (run_end - run_start);
+      out[1] = x;
+      x = y;
+      run_start = run_end;
+      run_end++;
+      if (run_end < src_size)
+        y = src_buf[run_end];
+      out += 2;
+      continue;
+    }
+    // Mismatched run
+    while (x != y && run_end <= run_start + max_len) {
+      out[run_end - run_start] = x;
+      x = y;
+      run_end++;
+      if (run_end == src_size) {
+        if (run_end <= run_start + max_len) {
+          out[run_end - run_start] = x;
+          run_end++;
+        }
+        break;
+      }
+      y = src_buf[run_end];
+    }
+    out[0] = run_end - run_start - 2;
+    out += run_end - run_start;
+    run_start = run_end - 1;
+  }
+  if (run_start < src_size) {  // 1 leftover character
+    out[0] = 0;
+    out[1] = x;
+    out += 2;
+  }
+  *out = 128;
+  *dest_size = out + 1 - *dest_buf;
+  return true;
 }
 
 bool CCodec_BasicModule::A85Encode(const uint8_t* src_buf,
                                    uint32_t src_size,
                                    uint8_t** dest_buf,
                                    uint32_t* dest_size) {
-  return false;
+  // Check inputs.
+  if (!src_buf || !dest_buf || !dest_size)
+    return false;
+
+  if (src_size == 0) {
+    *dest_size = 0;
+    return false;
+  }
+
+  // Worst case: 5 output for each 4 input (plus up to 4 from leftover), plus
+  // 2 character new lines each 75 output chars plus 2 termination chars. May
+  // have fewer if there are special "z" chars.
+  uint32_t est_size = 5 * (src_size / 4) + 4 + src_size / 30 + 2;
+  *dest_buf = FX_Alloc(uint8_t, est_size);
+
+  // Set up pointers.
+  uint8_t* out = *dest_buf;
+  uint32_t pos = 0;
+  uint32_t line_length = 0;
+  while (src_size >= 4 && pos < src_size - 3) {
+    uint32_t val = ((uint32_t)(src_buf[pos]) << 24) +
+                   ((uint32_t)(src_buf[pos + 1]) << 16) +
+                   ((uint32_t)(src_buf[pos + 2]) << 8) +
+                   (uint32_t)(src_buf[pos + 3]);
+    pos += 4;
+    if (val == 0) {  // All zero special case
+      *out = 'z';
+      out++;
+      line_length++;
+    } else {  // Compute base 85 characters and add 33.
+      for (int i = 4; i >= 0; i--) {
+        out[i] = (uint8_t)(val % 85) + 33;
+        val = val / 85;
+      }
+      out += 5;
+      line_length += 5;
+    }
+    if (line_length >= 75) {  // Add a return.
+      *out++ = '\r';
+      *out++ = '\n';
+      line_length = 0;
+    }
+  }
+  if (pos < src_size) {  // Leftover bytes
+    uint32_t val = 0;
+    int count = 0;
+    while (pos < src_size) {
+      val += (uint32_t)(src_buf[pos] << (8 * (3 - pos)));
+      count++;
+      pos++;
+    }
+    for (int i = 4; i >= 0; i--) {
+      if (i <= count)
+        out[i] = (uint8_t)(val % 85) + 33;
+      val = val / 85;
+    }
+    out += count + 1;
+  }
+
+  // Terminating characters.
+  out[0] = '~';
+  out[1] = '>';
+  out += 2;
+  *dest_size = out - *dest_buf;
+  return true;
 }
 
 #ifdef PDF_ENABLE_XFA
diff --git a/core/fxcodec/codec/fx_codec_a85_unittest.cpp b/core/fxcodec/codec/fx_codec_a85_unittest.cpp
new file mode 100644
index 0000000000..7910881772
--- /dev/null
+++ b/core/fxcodec/codec/fx_codec_a85_unittest.cpp
@@ -0,0 +1,209 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stdint.h>
+
+#include <limits>
+
+#include "core/fxcodec/codec/ccodec_basicmodule.h"
+#include "core/fxcodec/fx_codec.h"
+#include "testing/fx_string_testhelpers.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(fxcodec, A85TestBadInputs) {
+  uint8_t src_buf[4] = {1, 2, 3, 4};
+  uint8_t* dest_buf = nullptr;
+  uint32_t src_size = 4;
+  uint32_t dest_size = 0;
+
+  CCodec_BasicModule* pEncoders = CCodec_ModuleMgr().GetBasicModule();
+  EXPECT_TRUE(pEncoders);
+
+  // Error codes, not segvs, should callers pass us a nullptr pointer.
+  EXPECT_FALSE(pEncoders->A85Encode(src_buf, src_size, &dest_buf, nullptr));
+  EXPECT_FALSE(pEncoders->A85Encode(src_buf, src_size, nullptr, &dest_size));
+  EXPECT_FALSE(pEncoders->A85Encode(src_buf, 0, &dest_buf, &dest_size));
+  EXPECT_FALSE(pEncoders->A85Encode(nullptr, src_size, &dest_buf, &dest_size));
+}
+
+// No leftover bytes, just translate 2 sets of symbols.
+TEST(fxcodec, A85TestBasic) {
+  // Make sure really big values don't break.
+  uint8_t src_buf[8] = {1, 2, 3, 4, 255, 255, 255, 255};
+  uint8_t* dest_buf = nullptr;
+  uint32_t src_size = 8;
+  uint32_t dest_size = 0;
+
+  CCodec_BasicModule* pEncoders = CCodec_ModuleMgr().GetBasicModule();
+  EXPECT_TRUE(pEncoders);
+
+  // Should succeed.
+  EXPECT_TRUE(pEncoders->A85Encode(src_buf, src_size, &dest_buf, &dest_size));
+
+  // Should have 5 chars for each set of 4 and 2 terminators.
+  EXPECT_EQ(12u, dest_size);
+  uint8_t expected_out[12] = {33, 60, 78, 63, 43, 115, 56, 87, 45, 33, 126, 62};
+
+  // Check the output
+  for (uint32_t i = 0; i < 12; i++)
+    EXPECT_EQ(dest_buf[i], expected_out[i]) << " at " << i;
+  FX_Free(dest_buf);
+}
+
+// Leftover bytes.
+TEST(fxcodec, A85TestLeftoverBytes) {
+  // 1 Leftover Byte:
+  uint8_t src_buf_1leftover[5] = {1, 2, 3, 4, 255};
+  uint8_t* dest_buf = nullptr;
+  uint32_t src_size = 5;
+  uint32_t dest_size = 0;
+
+  CCodec_BasicModule* pEncoders = CCodec_ModuleMgr().GetBasicModule();
+  EXPECT_TRUE(pEncoders);
+
+  // Should succeed
+  EXPECT_TRUE(
+      pEncoders->A85Encode(src_buf_1leftover, src_size, &dest_buf, &dest_size));
+  EXPECT_EQ(9u, dest_size);  // 5 chars for first symbol + 2 + 2 terminators.
+  uint8_t expected_out_1leftover[9] = {33, 60, 78, 63, 43, 114, 114, 126, 62};
+
+  // Check the output
+  for (uint32_t i = 0; i < 9; i++)
+    EXPECT_EQ(dest_buf[i], expected_out_1leftover[i]) << " at " << i;
+  FX_Free(dest_buf);
+
+  // 2 Leftover bytes:
+  src_size++;
+  dest_buf = nullptr;
+  dest_size = 0;
+  uint8_t src_buf_2leftover[6] = {1, 2, 3, 4, 255, 254};
+  // Should succeed
+  EXPECT_TRUE(
+      pEncoders->A85Encode(src_buf_2leftover, src_size, &dest_buf, &dest_size));
+  EXPECT_EQ(10u, dest_size);  // 5 chars for first symbol + 3 + 2 terminators.
+  uint8_t expected_out_2leftover[10] = {33,  60, 78, 63,  43,
+                                        115, 56, 68, 126, 62};
+
+  // Check the output
+  for (uint32_t i = 0; i < 10; i++)
+    EXPECT_EQ(dest_buf[i], expected_out_2leftover[i]) << " at " << i;
+  FX_Free(dest_buf);
+
+  // 3 Leftover bytes:
+  src_size++;
+  dest_buf = nullptr;
+  dest_size = 0;
+  uint8_t src_buf_3leftover[7] = {1, 2, 3, 4, 255, 254, 253};
+  // Should succeed
+  EXPECT_TRUE(
+      pEncoders->A85Encode(src_buf_3leftover, src_size, &dest_buf, &dest_size));
+  EXPECT_EQ(11u, dest_size);  // 5 chars for first symbol + 4 + 2 terminators.
+  uint8_t expected_out_3leftover[11] = {33, 60, 78,  63,  43, 115,
+                                        56, 77, 114, 126, 62};
+
+  // Check the output
+  for (uint32_t i = 0; i < 11; i++)
+    EXPECT_EQ(dest_buf[i], expected_out_3leftover[i]) << " at " << i;
+  FX_Free(dest_buf);
+}
+
+// Test all zeros comes through as "z".
+TEST(fxcodec, A85TestZeros) {
+  // Make sure really big values don't break.
+  uint8_t src_buf[8] = {1, 2, 3, 4, 0, 0, 0, 0};
+  uint8_t* dest_buf = nullptr;
+  uint32_t src_size = 8;
+  uint32_t dest_size = 0;
+
+  CCodec_BasicModule* pEncoders = CCodec_ModuleMgr().GetBasicModule();
+  EXPECT_TRUE(pEncoders);
+
+  // Should succeed.
+  EXPECT_TRUE(pEncoders->A85Encode(src_buf, src_size, &dest_buf, &dest_size));
+
+  // Should have 5 chars for first set of 4 + 1 for z + 2 terminators.
+  EXPECT_EQ(8u, dest_size);
+  uint8_t expected_out[8] = {33, 60, 78, 63, 43, 122, 126, 62};
+
+  // Check the output
+  for (uint32_t i = 0; i < 8; i++)
+    EXPECT_EQ(dest_buf[i], expected_out[i]) << " at " << i;
+  FX_Free(dest_buf);
+
+  // Should also work if it is at the start:
+  dest_buf = nullptr;
+  dest_size = 0;
+  uint8_t src_buf_2[8] = {0, 0, 0, 0, 1, 2, 3, 4};
+
+  // Should succeed.
+  EXPECT_TRUE(pEncoders->A85Encode(src_buf_2, src_size, &dest_buf, &dest_size));
+
+  // Should have 5 chars for set of 4 + 1 for z + 2 terminators.
+  EXPECT_EQ(8u, dest_size);
+  uint8_t expected_out_2[8] = {122, 33, 60, 78, 63, 43, 126, 62};
+
+  // Check the output
+  for (uint32_t i = 0; i < 8; i++)
+    EXPECT_EQ(dest_buf[i], expected_out_2[i]) << " at " << i;
+  FX_Free(dest_buf);
+
+  // Try with 2 leftover zero bytes. Make sure we don't get a "z".
+  src_size = 6;  // Cut off the last 2 zeros.
+  dest_buf = nullptr;
+  dest_size = 0;
+
+  // Should succeed.
+  EXPECT_TRUE(pEncoders->A85Encode(src_buf, src_size, &dest_buf, &dest_size));
+
+  // Should have 5 chars for set of 4 + 3 for last 2 + 2 terminators.
+  EXPECT_EQ(10u, dest_size);
+  uint8_t expected_out_leftover[10] = {33, 60, 78, 63, 43, 33, 33, 33, 126, 62};
+
+  // Check the output
+  for (uint32_t i = 0; i < 10; i++)
+    EXPECT_EQ(dest_buf[i], expected_out_leftover[i]) << " at " << i;
+  FX_Free(dest_buf);
+}
+
+// Make sure we get returns in the expected locations.
+TEST(fxcodec, A85TestLineBreaks) {
+  // Make sure really big values don't break.
+  uint8_t src_buf[131] = {0};
+  // 1 full line + most of a line of normal symbols.
+  for (int k = 0; k < 116; k += 4) {
+    src_buf[k] = 1;
+    src_buf[k + 1] = 2;
+    src_buf[k + 2] = 3;
+    src_buf[k + 3] = 4;
+  }
+  // Fill in the end, leaving an all zero gap + 3 extra zeros at the end.
+  for (int k = 120; k < 128; k++) {
+    src_buf[k] = 1;
+    src_buf[k + 1] = 2;
+    src_buf[k + 2] = 3;
+    src_buf[k + 3] = 4;
+  }
+  uint8_t* dest_buf = nullptr;
+  uint32_t src_size = 131;
+  uint32_t dest_size = 0;
+
+  CCodec_BasicModule* pEncoders = CCodec_ModuleMgr().GetBasicModule();
+  EXPECT_TRUE(pEncoders);
+
+  // Should succeed.
+  EXPECT_TRUE(pEncoders->A85Encode(src_buf, src_size, &dest_buf, &dest_size));
+
+  // Should have 75 chars in the first row plus 2 char return,
+  // 76 chars in the second row plus 2 char return,
+  // and 9 chars in the last row with 2 terminators.
+  EXPECT_EQ(166u, dest_size);
+
+  // Check for the returns.
+  EXPECT_EQ(dest_buf[75], 13);
+  EXPECT_EQ(dest_buf[76], 10);
+  EXPECT_EQ(dest_buf[153], 13);
+  EXPECT_EQ(dest_buf[154], 10);
+
+  FX_Free(dest_buf);
+}
diff --git a/core/fxcodec/codec/fx_codec_rle_unittest.cpp b/core/fxcodec/codec/fx_codec_rle_unittest.cpp
new file mode 100644
index 0000000000..94d87cde92
--- /dev/null
+++ b/core/fxcodec/codec/fx_codec_rle_unittest.cpp
@@ -0,0 +1,195 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stdint.h>
+
+#include <limits>
+
+#include "core/fpdfapi/parser/fpdf_parser_decode.h"
+#include "core/fxcodec/codec/ccodec_basicmodule.h"
+#include "core/fxcodec/fx_codec.h"
+#include "testing/fx_string_testhelpers.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(fxcodec, RLETestBadInputs) {
+  uint8_t src_buf[1] = {1};
+  uint8_t* dest_buf = nullptr;
+  uint32_t src_size = 4;
+  uint32_t dest_size = 0;
+
+  CCodec_BasicModule* pEncoders = CCodec_ModuleMgr().GetBasicModule();
+  EXPECT_TRUE(pEncoders);
+
+  // Error codes, not segvs, should callers pass us a nullptr pointer.
+  EXPECT_FALSE(
+      pEncoders->RunLengthEncode(src_buf, src_size, &dest_buf, nullptr));
+  EXPECT_FALSE(
+      pEncoders->RunLengthEncode(src_buf, src_size, nullptr, &dest_size));
+  EXPECT_FALSE(pEncoders->RunLengthEncode(src_buf, 0, &dest_buf, &dest_size));
+  EXPECT_FALSE(
+      pEncoders->RunLengthEncode(nullptr, src_size, &dest_buf, &dest_size));
+}
+
+// Check length 1 input works. Check terminating character is applied.
+TEST(fxcodec, RLETestShortInput) {
+  uint8_t src_buf[1] = {1};
+  uint8_t* dest_buf = nullptr;
+  uint32_t src_size = 1;
+  uint32_t dest_size = 0;
+
+  CCodec_BasicModule* pEncoders = CCodec_ModuleMgr().GetBasicModule();
+  EXPECT_TRUE(pEncoders);
+
+  EXPECT_TRUE(
+      pEncoders->RunLengthEncode(src_buf, src_size, &dest_buf, &dest_size));
+  EXPECT_EQ(3u, dest_size);
+  EXPECT_EQ(dest_buf[0], 0);
+  EXPECT_EQ(dest_buf[1], 1);
+  EXPECT_EQ(dest_buf[2], 128);
+
+  FX_Free(dest_buf);
+}
+
+// Check a few basic cases (2 matching runs in a row, matching run followed
+// by a nonmatching run, and nonmatching run followed by a matching run).
+TEST(fxcodec, RLETestNormalInputs) {
+  // Match, match
+  uint8_t src_buf_1[10] = {2, 2, 2, 2, 4, 4, 4, 4, 4, 4};
+
+  // Match, nonmatch
+  uint8_t src_buf_2[10] = {2, 2, 2, 2, 1, 2, 3, 4, 5, 6};
+
+  // Nonmatch, match
+  uint8_t src_buf_3[10] = {1, 2, 3, 4, 5, 3, 3, 3, 3, 3};
+
+  uint32_t src_size = 10;
+  uint32_t dest_size = 0;
+  uint8_t* dest_buf = nullptr;
+
+  CCodec_BasicModule* pEncoders = CCodec_ModuleMgr().GetBasicModule();
+  EXPECT_TRUE(pEncoders);
+
+  // Case 1:
+  EXPECT_TRUE(
+      pEncoders->RunLengthEncode(src_buf_1, src_size, &dest_buf, &dest_size));
+  uint8_t* decoded_buf = nullptr;
+  uint32_t decoded_size = 0;
+  RunLengthDecode(dest_buf, dest_size, decoded_buf, decoded_size);
+  EXPECT_EQ(decoded_size, src_size);
+  for (uint32_t i = 0; i < src_size; i++)
+    EXPECT_EQ(decoded_buf[i], src_buf_1[i]) << " at " << i;
+  FX_Free(dest_buf);
+  FX_Free(decoded_buf);
+
+  // Case 2:
+  dest_buf = nullptr;
+  dest_size = 0;
+  EXPECT_TRUE(
+      pEncoders->RunLengthEncode(src_buf_2, src_size, &dest_buf, &dest_size));
+  decoded_buf = nullptr;
+  decoded_size = 0;
+  RunLengthDecode(dest_buf, dest_size, decoded_buf, decoded_size);
+  EXPECT_EQ(decoded_size, src_size);
+  for (uint32_t i = 0; i < src_size; i++)
+    EXPECT_EQ(decoded_buf[i], src_buf_2[i]) << " at " << i;
+  FX_Free(dest_buf);
+  FX_Free(decoded_buf);
+
+  // Case 3:
+  dest_buf = nullptr;
+  dest_size = 0;
+  EXPECT_TRUE(
+      pEncoders->RunLengthEncode(src_buf_3, src_size, &dest_buf, &dest_size));
+  decoded_buf = nullptr;
+  decoded_size = 0;
+  RunLengthDecode(dest_buf, dest_size, decoded_buf, decoded_size);
+  EXPECT_EQ(decoded_size, src_size);
+  for (uint32_t i = 0; i < src_size; i++)
+    EXPECT_EQ(decoded_buf[i], src_buf_3[i]) << " at " << i;
+  FX_Free(dest_buf);
+  FX_Free(decoded_buf);
+}
+
+// Check that runs longer than 128 are broken up properly, both matched and
+// nonmatched.
+TEST(fxcodec, RLETestFullLengthInputs) {
+  // Match, match
+  uint8_t src_buf_1[260] = {1};
+
+  // Match, nonmatch
+  uint8_t src_buf_2[260] = {2};
+  for (uint16_t i = 128; i < 260; i++)
+    src_buf_2[i] = (uint8_t)(i - 125);
+
+  // Nonmatch, match
+  uint8_t src_buf_3[260] = {3};
+  for (uint8_t i = 0; i < 128; i++)
+    src_buf_3[i] = i;
+
+  // Nonmatch, nonmatch
+  uint8_t src_buf_4[260];
+  for (uint16_t i = 0; i < 260; i++)
+    src_buf_4[i] = (uint8_t)(i);
+
+  uint32_t src_size = 260;
+  uint32_t dest_size = 0;
+  uint8_t* dest_buf = nullptr;
+
+  CCodec_BasicModule* pEncoders = CCodec_ModuleMgr().GetBasicModule();
+  EXPECT_TRUE(pEncoders);
+
+  // Case 1:
+  EXPECT_TRUE(
+      pEncoders->RunLengthEncode(src_buf_1, src_size, &dest_buf, &dest_size));
+  uint8_t* decoded_buf = nullptr;
+  uint32_t decoded_size = 0;
+  RunLengthDecode(dest_buf, dest_size, decoded_buf, decoded_size);
+  EXPECT_EQ(decoded_size, src_size);
+  for (uint32_t i = 0; i < src_size; i++)
+    EXPECT_EQ(decoded_buf[i], src_buf_1[i]) << " at " << i;
+  FX_Free(dest_buf);
+  FX_Free(decoded_buf);
+
+  // Case 2:
+  dest_buf = nullptr;
+  dest_size = 0;
+  EXPECT_TRUE(
+      pEncoders->RunLengthEncode(src_buf_2, src_size, &dest_buf, &dest_size));
+  decoded_buf = nullptr;
+  decoded_size = 0;
+  RunLengthDecode(dest_buf, dest_size, decoded_buf, decoded_size);
+  EXPECT_EQ(decoded_size, src_size);
+  for (uint32_t i = 0; i < src_size; i++)
+    EXPECT_EQ(decoded_buf[i], src_buf_2[i]) << " at " << i;
+  FX_Free(dest_buf);
+  FX_Free(decoded_buf);
+
+  // Case 3:
+  dest_buf = nullptr;
+  dest_size = 0;
+  EXPECT_TRUE(
+      pEncoders->RunLengthEncode(src_buf_3, src_size, &dest_buf, &dest_size));
+  decoded_buf = nullptr;
+  decoded_size = 0;
+  RunLengthDecode(dest_buf, dest_size, decoded_buf, decoded_size);
+  EXPECT_EQ(decoded_size, src_size);
+  for (uint32_t i = 0; i < src_size; i++)
+    EXPECT_EQ(decoded_buf[i], src_buf_3[i]) << " at " << i;
+  FX_Free(dest_buf);
+  FX_Free(decoded_buf);
+
+  // Case 4:
+  dest_buf = nullptr;
+  dest_size = 0;
+  EXPECT_TRUE(
+      pEncoders->RunLengthEncode(src_buf_4, src_size, &dest_buf, &dest_size));
+  decoded_buf = nullptr;
+  decoded_size = 0;
+  RunLengthDecode(dest_buf, dest_size, decoded_buf, decoded_size);
+  EXPECT_EQ(decoded_size, src_size);
+  for (uint32_t i = 0; i < src_size; i++)
+    EXPECT_EQ(decoded_buf[i], src_buf_4[i]) << " at " << i;
+  FX_Free(dest_buf);
+  FX_Free(decoded_buf);
+}