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authorWu, Ke <wuke@cs.umd.edu>2014-12-17 16:15:13 -0500
committerWu, Ke <wuke@cs.umd.edu>2014-12-17 16:15:13 -0500
commit6829a0bc624b02ebefc79f8cf9ec89d7d64a7c30 (patch)
tree125dfb20f73342873476c793995397b26fd202dd /klm/util/stream/block.hh
parentb455a108a21f4ba5a58ab1bc53a8d2bf4d829067 (diff)
parent7468e8d85e99b4619442c7afaf4a0d92870111bb (diff)
Merge branch 'const_reorder_2' into softsyn_2
Diffstat (limited to 'klm/util/stream/block.hh')
-rw-r--r--klm/util/stream/block.hh57
1 files changed, 53 insertions, 4 deletions
diff --git a/klm/util/stream/block.hh b/klm/util/stream/block.hh
index 11aa991e..aa7e28bb 100644
--- a/klm/util/stream/block.hh
+++ b/klm/util/stream/block.hh
@@ -1,5 +1,5 @@
-#ifndef UTIL_STREAM_BLOCK__
-#define UTIL_STREAM_BLOCK__
+#ifndef UTIL_STREAM_BLOCK_H
+#define UTIL_STREAM_BLOCK_H
#include <cstddef>
#include <stdint.h>
@@ -7,28 +7,77 @@
namespace util {
namespace stream {
+/**
+ * Encapsulates a block of memory.
+ */
class Block {
public:
+
+ /**
+ * Constructs an empty block.
+ */
Block() : mem_(NULL), valid_size_(0) {}
+ /**
+ * Constructs a block that encapsulates a segment of memory.
+ *
+ * @param[in] mem The segment of memory to encapsulate
+ * @param[in] size The size of the memory segment in bytes
+ */
Block(void *mem, std::size_t size) : mem_(mem), valid_size_(size) {}
+ /**
+ * Set the number of bytes in this block that should be interpreted as valid.
+ *
+ * @param[in] to Number of bytes
+ */
void SetValidSize(std::size_t to) { valid_size_ = to; }
- // Read might fill in less than Allocated at EOF.
+
+ /**
+ * Gets the number of bytes in this block that should be interpreted as valid.
+ * This is important because read might fill in less than Allocated at EOF.
+ */
std::size_t ValidSize() const { return valid_size_; }
+ /** Gets a void pointer to the memory underlying this block. */
void *Get() { return mem_; }
+
+ /** Gets a const void pointer to the memory underlying this block. */
const void *Get() const { return mem_; }
+
+ /**
+ * Gets a const void pointer to the end of the valid section of memory
+ * encapsulated by this block.
+ */
const void *ValidEnd() const {
return reinterpret_cast<const uint8_t*>(mem_) + valid_size_;
}
+ /**
+ * Returns true if this block encapsulates a valid (non-NULL) block of memory.
+ *
+ * This method is a user-defined implicit conversion function to boolean;
+ * among other things, this method enables bare instances of this class
+ * to be used as the condition of an if statement.
+ */
operator bool() const { return mem_ != NULL; }
+
+ /**
+ * Returns true if this block is empty.
+ *
+ * In other words, if Get()==NULL, this method will return true.
+ */
bool operator!() const { return mem_ == NULL; }
private:
friend class Link;
+
+ /**
+ * Points this block's memory at NULL.
+ *
+ * This class defines poison as a block whose memory pointer is NULL.
+ */
void SetToPoison() {
mem_ = NULL;
}
@@ -40,4 +89,4 @@ class Block {
} // namespace stream
} // namespace util
-#endif // UTIL_STREAM_BLOCK__
+#endif // UTIL_STREAM_BLOCK_H