From ee99fe39428005dae7554a3a80c16f46eb9e945c Mon Sep 17 00:00:00 2001
From: Hermet Park <hermet@lottiefiles.com>
Date: Mon, 27 May 2024 18:42:36 +0900
Subject: [PATCH] common/compressor: added djb2 encoder

This is useful for encoding the string into one long type value.
---
 src/common/tvgCompressor.cpp | 15 +++++++++++++++
 src/common/tvgCompressor.h   |  1 +
 2 files changed, 16 insertions(+)

diff --git a/src/common/tvgCompressor.cpp b/src/common/tvgCompressor.cpp
index 709cb22f..e7560e79 100644
--- a/src/common/tvgCompressor.cpp
+++ b/src/common/tvgCompressor.cpp
@@ -472,4 +472,19 @@ size_t b64Decode(const char* encoded, const size_t len, char** decoded)
 }
 
 
+/************************************************************************/
+/* DJB2 Implementation                                                   */
+/************************************************************************/
+
+unsigned long djb2Encode(const char* str)
+{
+    unsigned long hash = 5381;
+    int c;
+
+    while ((c = *str++)) {
+        hash = ((hash << 5) + hash) + c; // hash * 33 + c
+    }
+    return hash;
+}
+
 }
\ No newline at end of file
diff --git a/src/common/tvgCompressor.h b/src/common/tvgCompressor.h
index 0756127e..b043cc77 100644
--- a/src/common/tvgCompressor.h
+++ b/src/common/tvgCompressor.h
@@ -30,6 +30,7 @@ namespace tvg
     uint8_t* lzwEncode(const uint8_t* uncompressed, uint32_t uncompressedSizeBytes, uint32_t* compressedSizeBytes, uint32_t* compressedSizeBits);
     uint8_t* lzwDecode(const uint8_t* compressed, uint32_t compressedSizeBytes, uint32_t compressedSizeBits, uint32_t uncompressedSizeBytes);
     size_t b64Decode(const char* encoded, const size_t len, char** decoded);
+    unsigned long djb2Encode(const char* str);
 }
 
 #endif  //_TVG_COMPRESSOR_H_