2 files changed, 48 insertions, 0 deletions

diff --git a/ArchiveEx/Archive.cpp b/ArchiveEx/Archive.cpp
index 134404c..8ca7b71 100644
--- a/ArchiveEx/Archive.cpp
+++ b/ArchiveEx/Archive.cpp
@@ -23,6 +23,8 @@ static inline std::size_t ConvertPathSeparator(const char* src, char* dest);
 static constexpr std::uint32_t VERSION {0x0010};
 static constexpr std::size_t BLOCK_SIZE {1024};
 static constexpr std::size_t DIRECTORY_MARGIN {64};
+static constexpr int UNUSED_BLOCK {-1};
+static constexpr int DIRECTORY_BLOCK {-2};
 
 
 Archive::Archive(const char* p) :
@@ -56,6 +58,7 @@ Archive::Archive(const char* p) :
 		header.directory.compressed_size);
 	if (Z_OK != err)
 		throw "could not uncompress directory";
+	UpdateBlockMap();
 }
 
 
@@ -111,6 +114,29 @@ Archive::Find(const char* filepath) const
 
 
 void
+Archive::UpdateBlockMap()
+{
+	const std::size_t last_directory_block = header.directory.offset / BLOCK_SIZE + DirectoryBlocks() - 1;
+	std::size_t last_block = last_directory_block;
+	for (const auto& entry : entries) {
+		const std::size_t block = entry.offset / BLOCK_SIZE + BytesToBlocks(entry.compressed_size) - 1;
+		if (last_block < block)
+			last_block = block;
+	}
+	blocks.clear();
+	blocks.resize(last_block + 1, UNUSED_BLOCK);
+	for (std::size_t n = header.directory.offset / BLOCK_SIZE; n <= last_directory_block; ++n)
+		blocks[n] = DIRECTORY_BLOCK;
+	for (std::size_t i = 0; i < entries.size(); ++i) {
+		const std::size_t from = entries[i].offset / BLOCK_SIZE;
+		const std::size_t exclusive_to = from + BytesToBlocks(entries[i].compressed_size);
+		for (std::size_t n = from; n < exclusive_to; ++n)
+			blocks[n] = i;
+	}
+}
+
+
+void
 Archive::PrintNamesOfEntries() const
 {
 	for (const auto& entry : entries)
@@ -118,6 +144,25 @@ Archive::PrintNamesOfEntries() const
 }
 
 
+void
+Archive::PrintBlocks() const
+{
+	for (std::size_t i = 0; i < blocks.size(); ++i) {
+		std::printf("%ld\t", i);
+		switch (blocks[i]) {
+		case UNUSED_BLOCK:
+			std::printf("(unused)\n");
+			break;
+		case DIRECTORY_BLOCK:
+			std::printf("(dir)\n");
+			break;
+		default:
+			std::printf("%s\n", entries[blocks[i]].name);
+		}
+	}
+}
+
+
 std::size_t
 Archive::DirectoryBlocks() const
 {
diff --git a/ArchiveEx/Archive.h b/ArchiveEx/Archive.h
index cbaf571..e19c718 100644
--- a/ArchiveEx/Archive.h
+++ b/ArchiveEx/Archive.h
@@ -40,12 +40,15 @@ public:
 	int Expand(int index, std::uint8_t*& buffer, bool null_terminated=false) const;
 	int Expand(const char* filepath, std::uint8_t*& buffer, bool null_terminated=false) const;
 	int Find(const char* filepath) const;
+	void UpdateBlockMap();
 	void PrintNamesOfEntries() const;
+	void PrintBlocks() const;
 	std::size_t DirectoryBlocks() const;
 private:
 	const char* path;
 	Header header;
 	std::vector<Entry> entries;
+	std::vector<int> blocks;
 };