rtemstoolkit: Add a buffer helper class to insert and extract data.

1 files changed, 257 insertions, 0 deletions

diff --git a/rtemstoolkit/rld-buffer.h b/rtemstoolkit/rld-buffer.h
new file mode 100644
index 0000000..ea94a9a
--- /dev/null
+++ b/rtemstoolkit/rld-buffer.h
@@ -0,0 +1,257 @@
+/*
+ * Copyright (c) 2016, Chris Johns <chrisj@rtems.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/**
+ * @file
+ *
+ * @ingroup rtems-ld
+ *
+ * @brief A buffer of data.
+ *
+ */
+
+#if !defined (_RLD_BUFFER_H_)
+#define _RLD_BUFFER_H_
+
+#include <string>
+
+#include <rld-files.h>
+
+namespace rld
+{
+  namespace buffer
+  {
+    /**
+     * A buffer to help manage formats.
+     */
+    class buffer
+    {
+    public:
+      /**
+       * Create a buffer.
+       */
+      buffer (const size_t size, bool le = true);
+
+      /**
+       * An empty buffer
+       */
+      buffer ();
+
+      /**
+       * Copy a buffer.
+       */
+      buffer (const buffer& orig);
+
+      /*
+       * Destory the buffer.
+       */
+      ~buffer ();
+
+      /**
+       * Clear the buffer reseting the level to zero.
+       */
+      void clear ();
+
+      /**
+       * Write the data to the buffer.
+       *
+       * @param data The data to write to the buffer.
+       * @param length The amount of data in bytes to write.
+       */
+      void write (const void* data_, const size_t length);
+
+      /**
+       * Read the data from the buffer.
+       *
+       * @param data Read from the buffer in the data.
+       * @param length The amount of data in bytes to read.
+       */
+      void read (void* data_, const size_t length);
+
+      /**
+       * Fill the data to the buffer.
+       *
+       * @param length The amount of data in bytes to fill with.
+       * @param value The value to fill the buffer with.
+       */
+      void fill (const size_t length, const uint8_t value = 0);
+
+      /**
+       * Set the write pointer in the buffer to the level provided filing with
+       * the value also provided.
+       *
+       * @param out_ The new out pointer.
+       * @param value The value to fill the buffer with.
+       */
+      void set (const size_t out_, const uint8_t value = 0);
+
+      /**
+       * Skip the data in the buffer moving the read pointer.
+       *
+       * @param length The amount of data in bytes to skip.
+       */
+      void skip (const size_t length);
+
+      /**
+       * Rewind the in pointer the buffer to the pointer.
+       *
+       * @param in_ The new in pointer.
+       */
+      void rewind (const size_t in_);
+
+      /*
+       * The level in the buffer.
+       */
+      size_t level () const;
+
+      /*
+       * Write the data buffered to the image. Clear the buffer after.
+       */
+      void write (files::image& img);
+
+      /*
+       * Read the data from the image into the start of buffer.
+       */
+      void read (files::image& img, size_t length = 0);
+
+      /*
+       * Dump.
+       */
+      void dump ();
+
+    private:
+      uint8_t* data;    //< The data held in the buffer.
+      size_t   size;    //< The zie of the date the buffer hold.
+      bool     le;      //< True is little endian else it is big.
+      size_t   in;      //< The data in pointer, used when writing.
+      size_t   out;     //< The data out ponter, used when reading.
+      size_t   level_;  //< The level of data in the buffer.
+    };
+
+    /**
+     * Buffer template function for writing data to the buffer.
+     */
+    template < typename T >
+    void write (buffer& buf, const T value)
+    {
+      uint8_t bytes[sizeof (T)];
+      T       v = value;
+      int     b = sizeof (T) - 1;
+      while (b >= 0)
+      {
+        bytes[b--] = (uint8_t) v;
+        v >>= 8;
+      }
+      buf.write (bytes, sizeof (T));
+    }
+
+    /**
+     * Buffer template function for reading data to the buffer.
+     */
+    template < typename T >
+    void read (buffer& buf, T& value)
+    {
+      uint8_t bytes[sizeof (T)];
+      int     b = sizeof (T) - 1;
+      buf.read (bytes, sizeof(T));
+      value = 0;
+      while (b >= 0)
+      {
+        value <<= 8;
+        value |= (T) bytes[b--];
+      }
+    }
+
+    /*
+     * Insertion operators.
+     */
+    buffer& operator<< (buffer& buf, const uint64_t value);
+    buffer& operator<< (buffer& buf, const uint32_t value);
+    buffer& operator<< (buffer& buf, const uint16_t value);
+    buffer& operator<< (buffer& buf, const uint8_t value);
+    buffer& operator<< (buffer& buf, const std::string& str);
+
+    /*
+     * Extraction operators.
+     */
+    buffer& operator>> (buffer& buf, uint64_t& value);
+    buffer& operator>> (buffer& buf, uint32_t& value);
+    buffer& operator>> (buffer& buf, uint16_t& value);
+    buffer& operator>> (buffer& buf, uint8_t& value);
+
+    /*
+     * Buffer fill manipulator.
+     */
+    struct b_fill
+    {
+      const uint8_t value;
+      const size_t  amount;
+
+      b_fill (const size_t amount, const uint8_t value)
+        : value (value),
+          amount (amount) {
+      }
+
+      friend buffer& operator<< (buffer& buf, const b_fill& bf) {
+        buf.fill (bf.amount, bf.value);
+        return buf;
+      }
+    };
+
+    b_fill fill (const size_t amount, const uint8_t value = 0);
+
+    /*
+     * Buffer set manipulator.
+     */
+    struct b_set
+    {
+      const uint8_t value;
+      const size_t  level;
+
+      b_set (const size_t level, const uint8_t value)
+        : value (value),
+          level (level) {
+      }
+
+      friend buffer& operator<< (buffer& buf, const b_set& bs) {
+        buf.set (bs.level, bs.value);
+        return buf;
+      }
+    };
+
+    b_set set (const size_t level, const uint8_t value = 0);
+
+    /*
+     * Buffer skip manipulator.
+     */
+    struct b_skip
+    {
+      const size_t amount;
+
+      b_skip (const size_t amount)
+        : amount (amount) {
+      }
+
+      friend buffer& operator>> (buffer& buf, const b_skip& bs) {
+        buf.skip (bs.amount);
+        return buf;
+      }
+    };
+
+    b_skip skip (const size_t amount);
+  }
+}
+
+#endif