MAINT-6584: Streamline static LLImageJ2C implementation API.

Specifically, remove unused function pointer types CreateLLImageJ2CFunction,
DestroyLLImageJ2CFunction and EngineInfoLLImageJ2CFunction.

Also eliminate static fallbackDestroyLLImageJ2CImpl() and
fallbackEngineInfoLLImageJ2CImpl(), leaving only static
fallbackCreateLLImageJ2CImpl().

We do need a factory function to instantiate the appropriate LLImageJ2CImpl
subclass, so leave the fallbackCreateLLImageJ2CImpl() link seam in place.

However, given that every known LLImageJ2CImpl subclass is cheap to
instantiate, make getEngineInfo() a pure virtual method on that subclass: the
static LLImageJ2C::getEngineInfo() method can temporarily construct an
instance to query. While we're at it, make getEngineInfo() return std::string
like LLImageJ2C::getEngineInfo(). It's ridiculous that
fallbackEngineInfoLLImageJ2CImpl() implementations constructed a static
std::string and returned its c_str(), only to have LLImageJ2C::getEngineInfo()
construct ANOTHER std::string from the returned const char*.

fallbackDestroyLLImageJ2CImpl() never did anything useful: it merely deleted
the passed LLImageJ2CImpl subclass pointer as the specific subclass type. But
since LLImageJ2CImpl's destructor is virtual, LLImageJ2C's destructor could
simply delete the stored LLImageJ2CImpl*. In fact, make mImpl a
boost::scoped_ptr<LLImageJ2CImpl> so we don't even have to delete it manually.

2 files changed, 10 insertions, 16 deletions

diff --git a/indra/llimagej2coj/llimagej2coj.cpp b/indra/llimagej2coj/llimagej2coj.cpp
index e98f677d9b..0152b879c2 100644
--- a/indra/llimagej2coj/llimagej2coj.cpp
+++ b/indra/llimagej2coj/llimagej2coj.cpp
@@ -33,23 +33,16 @@
 #include "lltimer.h"
 //#include "llmemory.h"
 
-const char* fallbackEngineInfoLLImageJ2CImpl()
-{
-	static std::string version_string =
-		std::string("OpenJPEG: " OPENJPEG_VERSION ", Runtime: ")
-		+ opj_version();
-	return version_string.c_str();
-}
-
+// Factory function: see declaration in llimagej2c.cpp
 LLImageJ2CImpl* fallbackCreateLLImageJ2CImpl()
 {
 	return new LLImageJ2COJ();
 }
 
-void fallbackDestroyLLImageJ2CImpl(LLImageJ2CImpl* impl)
+std::string LLImageJ2COJ::getEngineInfo() const
 {
-	delete impl;
-	impl = NULL;
+	return std::string("OpenJPEG: " OPENJPEG_VERSION ", Runtime: ")
+		+ opj_version();
 }
 
 // Return string from message, eliminating final \n if present
diff --git a/indra/llimagej2coj/llimagej2coj.h b/indra/llimagej2coj/llimagej2coj.h
index 40ad4edb00..ae96a175a2 100644
--- a/indra/llimagej2coj/llimagej2coj.h
+++ b/indra/llimagej2coj/llimagej2coj.h
@@ -35,12 +35,13 @@ public:
 	LLImageJ2COJ();
 	virtual ~LLImageJ2COJ();
 protected:
-	/*virtual*/ BOOL getMetadata(LLImageJ2C &base);
-	/*virtual*/ BOOL decodeImpl(LLImageJ2C &base, LLImageRaw &raw_image, F32 decode_time, S32 first_channel, S32 max_channel_count);
-	/*virtual*/ BOOL encodeImpl(LLImageJ2C &base, const LLImageRaw &raw_image, const char* comment_text, F32 encode_time=0.0,
+	virtual BOOL getMetadata(LLImageJ2C &base);
+	virtual BOOL decodeImpl(LLImageJ2C &base, LLImageRaw &raw_image, F32 decode_time, S32 first_channel, S32 max_channel_count);
+	virtual BOOL encodeImpl(LLImageJ2C &base, const LLImageRaw &raw_image, const char* comment_text, F32 encode_time=0.0,
 								BOOL reversible = FALSE);
-	/*virtual*/ BOOL initDecode(LLImageJ2C &base, LLImageRaw &raw_image, int discard_level = -1, int* region = NULL);
-	/*virtual*/ BOOL initEncode(LLImageJ2C &base, LLImageRaw &raw_image, int blocks_size = -1, int precincts_size = -1, int levels = 0);
+	virtual BOOL initDecode(LLImageJ2C &base, LLImageRaw &raw_image, int discard_level = -1, int* region = NULL);
+	virtual BOOL initEncode(LLImageJ2C &base, LLImageRaw &raw_image, int blocks_size = -1, int precincts_size = -1, int levels = 0);
+    virtual std::string getEngineInfo() const;
 };
 
 #endif