1 files changed, 154 insertions, 0 deletions
diff --git a/source/archived/network_compression.c b/source/archived/network_compression.c
new file mode 100644
index 0000000..eef9e3c
--- /dev/null
+++ b/source/archived/network_compression.c
@@ -0,0 +1,154 @@
+#include <strings.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <wchar.h>
+#include <fcntl.h>
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+typedef int8_t s8;
+typedef int16_t s16;
+typedef int32_t s32;
+typedef int64_t s64;
+
+size_t
+GetMaximumCompressedOutputSize(size_t FileSize)
+{
+    // TODO: figure out equation
+    return FileSize*2 + 256;
+}
+
+u32
+RLECompress(size_t InSize, u8* In, size_t MaxOutSize, u8* OutBase)
+{
+    u8* Out = OutBase;
+
+#define MAX_LITERAL_COUNT 255
+#define MAX_RUN_COUNT 255
+    u32 LiteralCount = 0;
+    u8 Literals[MAX_LITERAL_COUNT] = {0};
+
+    u8 *InEnd = In + InSize;
+    while(In < InEnd)
+    {
+        u8 StartingValue = In[0];
+        size_t Run = 1; // first one is the character itself
+        while((Run < (InEnd - In)) &&
+              (Run < MAX_RUN_COUNT) &&
+              (In[Run] == StartingValue))
+        {
+            ++Run;
+        }
+
+        if ((Run > 1) ||
+            (LiteralCount == MAX_LITERAL_COUNT)) // stop doing runs when there is no
+                                                // space left in the buffer.
+        {
+            // Encode a literal/run pair
+            u8 LiteralCount8 = (u8)LiteralCount;
+            assert(LiteralCount8 == LiteralCount);
+            *Out++ = LiteralCount8;
+
+            for(u32 LiteralIndex = 0;
+                LiteralIndex < LiteralCount;
+                ++LiteralIndex)
+            {
+                *Out++ = Literals[LiteralIndex];
+            }
+            LiteralCount = 0;
+
+            u8 Run8 = (u8)Run;
+            assert(Run8 == Run);
+            *Out++ = Run8;
+
+            *Out++ = StartingValue;
+
+            In += Run;
+        }
+        else
+        {
+            // Buffer literals, you have to because we are encoding them in pairs
+            Literals[LiteralCount++] = StartingValue;
+            ++In;
+        }
+
+    }
+#undef MAX_LITERAL_COUNT
+#undef MAX_RUN_COUNT
+
+    assert(In == InEnd);
+
+    size_t OutSize = Out - OutBase;
+    assert(OutSize <= MaxOutSize);
+
+    return OutSize;
+}
+
+void
+RLEDecompress(size_t InSize, u8* In, size_t OutSize, u8* Out)
+{
+    u8 *InEnd = In + InSize;
+    while(In < InEnd)
+    {
+        // TODO: I think Casey made a mistake and this should be an u8
+        u8 LiteralCount = *In++;
+        while(LiteralCount--)
+        {
+            *Out++ = *In++;
+        }
+
+        // Alternate to Run
+        u8 RepCount = *In++;
+        u8 RepValue = *In++;
+        while(RepCount--)
+        {
+            *Out++ = RepValue;
+        }
+    }
+
+    assert(In == InEnd);
+}
+
+int main(int Argc, char* Argv[]) {
+
+    if (Argc < 2)
+    {
+        fprintf(stderr, "Usage: %s [compress|decompress]\n", Argv[0]);
+        return 1;
+    }
+
+    char* Command = Argv[1];
+
+    if (!strcmp(Command, "compress"))
+    {
+        u32* Message = (u32*)L"abcabcbbbbbbb";
+        size_t MessageSize = wcslen((const wchar_t*)Message) * 4;
+        
+        size_t OutBufferSize = GetMaximumCompressedOutputSize(MessageSize);
+        u8 OutBuffer[OutBufferSize + 8];
+        bzero(OutBuffer, OutBufferSize + 8);
+        *(u32*)OutBuffer = MessageSize;
+
+        size_t CompressedSize = RLECompress(MessageSize, (u8*)Message, OutBufferSize, OutBuffer + 8);
+
+        s32 OutFile = open("test.compressed", O_WRONLY | O_CREAT, 0600);
+
+        write(OutFile, OutBuffer, CompressedSize);
+
+        fprintf(stdout, "%lu -> %lu bytes\n", MessageSize, CompressedSize);
+    }
+    else if (!strcmp(Command, "decompress"))
+    {
+        fprintf(stderr, "Not implemented yet.\n");
+    }
+    else
+        fprintf(stderr, "Unknown command: '%s'\n", Command);
+
+    return 0;
+}