From 55a74f58896c603cbf69ae4b657656ea071b9e6b Mon Sep 17 00:00:00 2001
From: Andrej Babic <andrej.babic@psi.ch>
Date: Wed, 13 May 2020 15:20:20 +0200
Subject: [PATCH] Test concat of separately compressed segments

---
 core-buffer/test/test_bitshuffle.cpp | 72 +++++++++++++++++++++++++++-
 1 file changed, 71 insertions(+), 1 deletion(-)

diff --git a/core-buffer/test/test_bitshuffle.cpp b/core-buffer/test/test_bitshuffle.cpp
index 7f7a919..cc4ca45 100644
--- a/core-buffer/test/test_bitshuffle.cpp
+++ b/core-buffer/test/test_bitshuffle.cpp
@@ -8,7 +8,7 @@ TEST(bitshuffle, simple_compression)
 {
     auto size = MODULE_N_PIXELS;
     auto elem_size = 2; // uint16_t
-    auto block_size = MODULE_N_BYTES;
+    auto block_size = MODULE_N_PIXELS;
 
     auto compress_buffer_size = bshuf_compress_lz4_bound(
             size, elem_size, block_size);
@@ -38,4 +38,74 @@ TEST(bitshuffle, simple_compression)
     for (size_t i=0; i<MODULE_N_PIXELS; i++) {
         ASSERT_EQ(out_frame_buffer[i], frame_buffer[i]);
     }
+}
+
+TEST(bitshuffle, separate_compression)
+{
+    auto size = MODULE_N_PIXELS;
+    auto elem_size = 2; // uint16_t
+    auto block_size = MODULE_N_PIXELS;
+
+    auto compress_buffer_size = bshuf_compress_lz4_bound(
+            size, elem_size, block_size);
+    auto frame_buffer = make_unique<uint16_t[]>(MODULE_N_PIXELS);
+
+    // Set specific values to pixels and compress each chunk individually.
+    auto compress_buffer_1 = make_unique<char[]>(compress_buffer_size);
+    for (size_t i=0; i<MODULE_N_PIXELS; i++) {
+        frame_buffer[i] = i%100;
+    }
+    auto compressed_size_1 = bshuf_compress_lz4(
+            frame_buffer.get(), compress_buffer_1.get(),
+            size, elem_size, block_size);
+    ASSERT_TRUE(compressed_size_1 > 0);
+
+    auto compress_buffer_2 = make_unique<char[]>(compress_buffer_size);
+    for (size_t i=0; i<MODULE_N_PIXELS; i++) {
+        frame_buffer[i] = (i%100) + 100;
+    }
+    auto compressed_size_2 = bshuf_compress_lz4(
+            frame_buffer.get(), compress_buffer_2.get(),
+            size, elem_size, block_size);
+    ASSERT_TRUE(compressed_size_2 > 0);
+
+    // Allocate common compression buffer to concat them together.
+    auto sum_compressed_size = compressed_size_1 + compressed_size_2;
+    auto sum_compressed_buffer = make_unique<char[]>(sum_compressed_size);
+
+    // Concat the 2 buffers one after the other.
+    memcpy(
+            &(sum_compressed_buffer[0]),
+            &(compress_buffer_1[0]),
+            compressed_size_1);
+    memcpy(
+            &(sum_compressed_buffer[compressed_size_1]),
+            &(compress_buffer_2[0]),
+            compressed_size_2);
+
+    // Verify that the memcpy was correct.
+    for (size_t i=0; i<compressed_size_1; i++) {
+        ASSERT_EQ(sum_compressed_buffer[i], compress_buffer_1[i]);
+    }
+    auto offset = compressed_size_1;
+    for (size_t i=0; i<compressed_size_2; i++) {
+        ASSERT_EQ(sum_compressed_buffer[offset+i], compress_buffer_2[i]);
+    }
+
+    // Decompress concat buffer to new frame.
+    auto out_frame_buffer = make_unique<uint16_t[]>(MODULE_N_PIXELS*2);
+    auto consumed_bytes = bshuf_decompress_lz4(
+            sum_compressed_buffer.get(), out_frame_buffer.get(),
+            size*2, elem_size, block_size);
+    ASSERT_EQ(consumed_bytes, sum_compressed_size);
+
+    // Verify that concat output buffer has correct specific values.
+    for (size_t i=0;i<MODULE_N_PIXELS*2;i++) {
+        if (i<MODULE_N_PIXELS) {
+            ASSERT_EQ(out_frame_buffer[i], i%100);
+        } else {
+            auto i_adj = i - MODULE_N_PIXELS;
+            ASSERT_EQ(out_frame_buffer[i], (i_adj%100) + 100);
+        }
+    }
 }
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