Generalized LZ-style decompression; extend MveDecoder to decode in-flight MVEs

TreFile.hh

@@ -6,6 +6,7 @@
 #include <cstdio>
 #include <vector>
 #include <tuple>
+#include <experimental/optional>
 
 class TreFile {
 public:
@@ -29,22 +30,28 @@ public:
     
     Object(Object const& copy) = delete;
     Object(Object && move)
-      : base_(move.base_), length_(move.length_) {
+      : data_(std::move(move.data_)), base_(move.base_), length_(move.length_) {
+      move.data_ = std::experimental::nullopt;
       move.base_ = nullptr;
       move.length_ = 0;
     }
 
     Object& operator=(Object const& copy) = delete;
     Object& operator=(Object && move) {
+      data_ = std::move(move.data_);
       base_ = move.base_;
       length_ = move.length_;
+      move.data_ = std::experimental::nullopt;
       move.base_ = nullptr;
       move.length_ = 0;
       return *this;
     }
     
     char const* data() const {
-      return base_;
+      if (data_)
+	return (char const*)(data_->data());
+      else
+	return base_;
     }
     
     size_t size() const {
@@ -52,20 +59,32 @@ public:
     }
 
     operator bool() const {
-      return base_;
+      return data_ || base_;
     }
     
   private:
+    // Object either owns data (when decompressed) ...
+    std::experimental::optional<std::vector<uint8_t> > data_;
+    // .. or points to area in underlying data (when not compressed)
     char const* base_;
     size_t length_;
 
     Object(char const* base, size_t length)
-      : base_(base), length_(length) {
+      : data_(), base_(base), length_(length) {
     }
 
+    Object(std::vector<uint8_t> data)
+      : data_(std::move(data)), base_(nullptr), length_(data_->size()) {
+    }
+    
     friend class TreFile;
   };
 
+  /* Open an object of the TRE file by name or by CRC
+   * The returned object should be destroyed when no longer needed as it may
+   * hold a memory allocation for its data. But it must not be used after the
+   * TreFile object is destroyed.
+   */
   Object openName(std::string const& name) const;
   Object openCRC(uint32_t crc) const;