From 454297253cbf3b7ff262792c0e7c9a69f5cfb6b9 Mon Sep 17 00:00:00 2001
From: Rodrigo Braz Monteiro <zeratul@cellosoft.com>
Date: Mon, 3 Apr 2006 16:23:53 +0000
Subject: [PATCH] Change PRS header, fixed some exception handling and added a
 (not coded) PRSFile::LoadText function

Originally committed to SVN as r297.
---
 avisynth_prs/draw_prs.cpp |  7 +++--
 prs/prs_file.cpp          | 58 +++++++++++++++++++++++++++++----------
 prs/prs_file.h            |  3 ++
 3 files changed, 52 insertions(+), 16 deletions(-)

diff --git a/avisynth_prs/draw_prs.cpp b/avisynth_prs/draw_prs.cpp
index bb140a8c8..e4bb048fa 100644
--- a/avisynth_prs/draw_prs.cpp
+++ b/avisynth_prs/draw_prs.cpp
@@ -54,8 +54,11 @@ DrawPRS::DrawPRS (IScriptEnvironment* _env, PClip _child, const char *filename)
 	}
 
 	// Catch exception
-	catch (std::exception e) {
-		env->ThrowError(e.what());
+	catch (const std::exception &e) {
+		env->ThrowError("Error in PRS loading: %s",e.what());
+	}
+	catch (...) {
+		env->ThrowError("Unhandled exception in PRS loading.");
 	}
 }
 
diff --git a/prs/prs_file.cpp b/prs/prs_file.cpp
index 9415dd3d3..3765f7911 100644
--- a/prs/prs_file.cpp
+++ b/prs/prs_file.cpp
@@ -96,11 +96,11 @@ void PRSFile::Save(std::string path) {
 
 	// Open file
 	FILE *fp = fopen(path.c_str(),"wb");
-	if (!fp) throw new std::exception("Failed to open file");
+	if (!fp) throw std::exception("Failed to open file");
 
 	try {
 		// Write the "PRS" (zero-terminated) string ID (4 bytes)
-		fwrite("PRS",1,4,fp);
+		fwrite("PRS-BIN",1,8,fp);
 
 		// Write version number (4 bytes)
 		unsigned __int32 temp = 1;
@@ -144,19 +144,27 @@ void PRSFile::Load(std::string path, bool reset) {
 
 	// Open file
 	FILE *fp = fopen(path.c_str(),"rb");
-	if (!fp) throw new std::exception("Failed to open file");
+	if (!fp) throw std::exception("Failed to open file");
 
 	try {
-		// Read first four bytes
-		char buf[5];
-		buf[4] = 0;
-		fread(buf,1,4,fp);
-		if (strcmp(buf,"PRS") != 0) throw new std::exception("Invalid file type.");
+		// Read first eight bytes
+		char buf[16];
+		fread(buf,1,8,fp);
+		if (memcmp(buf,"PRS-BIN",8) != 0) {
+			// Is actually ASCII, read as that
+			if (memcmp(buf,"PRS-ASC",7) == 0) {
+				LoadText(path,false);
+				return;
+			}
+
+			// Invalid
+			throw std::exception("Invalid file type.");
+		}
 
 		// Read version number
 		unsigned __int32 temp = 0;
 		fread(&temp,4,1,fp);
-		if (temp != 1) throw new std::exception("Invalid version.");
+		if (temp != 1) throw std::exception("Invalid version.");
 
 		// Read stream name length
 		fread(&temp,4,1,fp);
@@ -309,11 +317,8 @@ PRSVideoFrame* PRSFile::CachedGetFrameByID(int id) {
 		cached.frame = NULL;
 		cacheMemSize += frame->GetSize();
 
-		// If memory has been exceeded, remove stuff from the back until it isn't anymore
-		while (cacheMemSize > maxCache && frameCache.size() > 1) {
-			cacheMemSize -= frameCache.back().frame->GetSize();
-			frameCache.pop_back();
-		}
+		// Update cache
+		EnforceCacheLimit();
 	}
 
 	// Return it
@@ -321,6 +326,25 @@ PRSVideoFrame* PRSFile::CachedGetFrameByID(int id) {
 }
 
 
+/////////////////////////////////////////////////////////////
+// Enforce the cache limit, that is, delete anything over it
+// This function will always leave at least one image on cache
+void PRSFile::EnforceCacheLimit() {
+	while (cacheMemSize > maxCache && frameCache.size() > 1) {
+		cacheMemSize -= frameCache.back().frame->GetSize();
+		frameCache.pop_back();
+	}
+}
+
+
+////////////////////////////
+// Set maximum cache memory
+void PRSFile::SetCacheLimit(int bytes) {
+	maxCache = bytes;
+	EnforceCacheLimit();
+}
+
+
 ////////////////////////////////////////////////
 // Finds which display blocks are at a position
 void PRSFile::GetDisplayBlocksAtFrame(int n,std::vector<PRSDisplay*> &blocks) {
@@ -430,3 +454,9 @@ void PRSFile::SaveText(std::string path) {
 	// Close file
 	file.close();
 }
+
+
+///////////////////
+// Load plain-text
+void PRSFile::LoadText(std::string path, bool reset) {
+}
diff --git a/prs/prs_file.h b/prs/prs_file.h
index 455931840..96cdd67fb 100644
--- a/prs/prs_file.h
+++ b/prs/prs_file.h
@@ -60,6 +60,7 @@ private:
 	int cacheMemSize;
 	int maxCache;
 	void Reset();
+	void EnforceCacheLimit();
 
 public:
 	PRSFile();
@@ -77,8 +78,10 @@ public:
 	bool HasDataAtFrame(int n);
 	void DrawFrame(int n,PRSVideoFrame *frame);
 	PRSImage *GetImageByID(int id);
+
 	PRSVideoFrame *CachedGetFrameByID(int id);
 	void ClearCache();
+	void SetCacheLimit(int bytes);
 
 	PRSImage *FindDuplicateImage(PRSImage *img);
 };