Add tests for find_decompressed_size with skippable frames (#68)

* Add tests for `find_decompressed_size` with skippable frames * add `create_skippable_frame` test util
JuliaIO · Sep 15, 2024 · cef9aaa · cef9aaa
1 parent bcebbb0
commit cef9aaa
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Showing 3 changed files with 51 additions and 12 deletions.
diff --git a/test/runtests.jl b/test/runtests.jl
@@ -11,6 +11,8 @@ using Test
 
 Random.seed!(1234)
 
+include("utils.jl")
+
 @testset "Zstd Codec" begin
     codec = ZstdCompressor()
     @test codec isa ZstdCompressor
@@ -42,6 +44,17 @@ Random.seed!(1234)
         end
     end
 
+    @testset "skippable frames" begin
+        skippable_frame = create_skippable_frame(b"\r\0\0\0")
+        u1 = collect(b"")
+        u2 = collect(b"Hello World!")
+        c1 = transcode(ZstdCompressor, u1)
+        c2 = transcode(ZstdCompressor, u2)
+        @test transcode(ZstdDecompressor, skippable_frame) == UInt8[]
+        @test transcode(ZstdDecompressor, [skippable_frame; c1;]) == u1
+        @test transcode(ZstdDecompressor, [skippable_frame; c2;]) == u2
+    end
+
     @test ZstdCompressorStream <: TranscodingStreams.TranscodingStream
     @test ZstdDecompressorStream <: TranscodingStreams.TranscodingStream
 
@@ -91,9 +104,9 @@ Random.seed!(1234)
     end
 
     @testset "find_decompressed_size" begin
-        codec = ZstdFrameCompressor()
-        buffer1 = transcode(codec, "Hello")
-        buffer2 = transcode(codec, "World!")
+        codec = ZstdFrameCompressor
+        buffer1 = transcode(codec, b"Hello")
+        buffer2 = transcode(codec, b"World!")
         @test CodecZstd.find_decompressed_size(buffer1) == 5
         @test CodecZstd.find_decompressed_size(buffer2) == 6
 
@@ -116,9 +129,9 @@ Random.seed!(1234)
         v = take!(iob)
         @test CodecZstd.find_decompressed_size(v) == 22
 
-        codec = ZstdCompressor()
-        buffer3 = transcode(codec, "Hello")
-        buffer4 = transcode(codec, "World!")
+        codec = ZstdCompressor
+        buffer3 = transcode(codec, b"Hello")
+        buffer4 = transcode(codec, b"World!")
         @test CodecZstd.find_decompressed_size(buffer3) == CodecZstd.ZSTD_CONTENTSIZE_UNKNOWN
         @test CodecZstd.find_decompressed_size(buffer4) == CodecZstd.ZSTD_CONTENTSIZE_UNKNOWN
 

diff --git a/test/static_only_tests.jl b/test/static_only_tests.jl
@@ -8,11 +8,12 @@ These tests use the static-only API to test `find_decompressed_size`
 """
 
 @testset "find_decompressed_size (with static-only API)" begin
-    codec = ZstdFrameCompressor()
-    buffer1 = transcode(codec, "Hello")
-    buffer2 = transcode(codec, "World!")
+    codec = ZstdFrameCompressor
+    buffer1 = transcode(codec, b"Hello")
+    buffer2 = transcode(codec, b"World!")
     LibZstdStatic.ZSTD_findDecompressedSize(b::Vector{UInt8}) = LibZstdStatic.ZSTD_findDecompressedSize(b, length(b))
     @test CodecZstd.find_decompressed_size(buffer1) == LibZstdStatic.ZSTD_findDecompressedSize(buffer1)
+    @test CodecZstd.find_decompressed_size(buffer1) == 5
     @test CodecZstd.find_decompressed_size(buffer2) == LibZstdStatic.ZSTD_findDecompressedSize(buffer2)
 
     iob = IOBuffer()
@@ -34,9 +35,9 @@ These tests use the static-only API to test `find_decompressed_size`
     v = take!(iob)
     @test CodecZstd.find_decompressed_size(v) == LibZstdStatic.ZSTD_findDecompressedSize(v)
 
-    codec = ZstdCompressor()
-    buffer3 = transcode(codec, "Hello")
-    buffer4 = transcode(codec, "World!")
+    codec = ZstdCompressor
+    buffer3 = transcode(codec, b"Hello")
+    buffer4 = transcode(codec, b"World!")
     @test CodecZstd.find_decompressed_size(buffer3) == LibZstdStatic.ZSTD_findDecompressedSize(buffer3)
     @test CodecZstd.find_decompressed_size(buffer4) == LibZstdStatic.ZSTD_findDecompressedSize(buffer4)
 
@@ -60,4 +61,16 @@ These tests use the static-only API to test `find_decompressed_size`
         @test CodecZstd.find_decompressed_size(pointer(v), length(buffer1)) == LibZstdStatic.ZSTD_findDecompressedSize(v, length(buffer1))
     end
     @test CodecZstd.find_decompressed_size(v) == LibZstdStatic.ZSTD_findDecompressedSize(v)
+
+    @testset "skippable frames" begin
+        skippable_frame = create_skippable_frame(b"\r\0\0\0")
+        @test CodecZstd.find_decompressed_size(skippable_frame) == LibZstdStatic.ZSTD_findDecompressedSize(skippable_frame)
+        @test CodecZstd.find_decompressed_size(skippable_frame) == 0
+        for d in 0:2
+            v = vcat(circshift([buffer1, skippable_frame, buffer2], d)...)
+            @test CodecZstd.find_decompressed_size(v) == LibZstdStatic.ZSTD_findDecompressedSize(v)
+            @test CodecZstd.find_decompressed_size(v) == 11
+        end
+    end
+
 end
diff --git a/test/utils.jl b/test/utils.jl
@@ -0,0 +1,13 @@
+"""
+    create_skippable_frame(user_data::AbstractVector{UInt8}, magic_number::UInt32=0x184D2A50)::Vector{UInt8}
+
+Return a skippable frame containing `user_data`.
+"""
+function create_skippable_frame(user_data::AbstractVector{UInt8}, magic_number::UInt32=0x184D2A50)
+    @assert magic_number ∈ 0x184D2A50:0x184D2A5F
+    UInt8[
+        reinterpret(UInt8, [htol(magic_number)]);
+        reinterpret(UInt8, [htol(UInt32(length(user_data)))]);
+        user_data;
+    ]
+end