1 files changed, 43 insertions, 0 deletions
diff --git a/klm/util/stream/block.hh b/klm/util/stream/block.hh
new file mode 100644
index 00000000..11aa991e
--- /dev/null
+++ b/klm/util/stream/block.hh
@@ -0,0 +1,43 @@
+#ifndef UTIL_STREAM_BLOCK__
+#define UTIL_STREAM_BLOCK__
+
+#include <cstddef>
+#include <stdint.h>
+
+namespace util {
+namespace stream {
+
+class Block {
+  public:
+    Block() : mem_(NULL), valid_size_(0) {}
+
+    Block(void *mem, std::size_t size) : mem_(mem), valid_size_(size) {}
+
+    void SetValidSize(std::size_t to) { valid_size_ = to; }
+    // Read might fill in less than Allocated at EOF.   
+    std::size_t ValidSize() const { return valid_size_; }
+
+    void *Get() { return mem_; }
+    const void *Get() const { return mem_; }
+
+    const void *ValidEnd() const { 
+      return reinterpret_cast<const uint8_t*>(mem_) + valid_size_;
+    }
+
+    operator bool() const { return mem_ != NULL; }
+    bool operator!() const { return mem_ == NULL; }
+ 
+  private:
+    friend class Link;
+    void SetToPoison() {
+      mem_ = NULL;
+    }
+
+    void *mem_;
+    std::size_t valid_size_;
+};
+
+} // namespace stream
+} // namespace util
+
+#endif // UTIL_STREAM_BLOCK__