1 files changed, 179 insertions, 0 deletions
diff --git a/cpukit/libdl/rtl-obj-comp.c b/cpukit/libdl/rtl-obj-comp.c
new file mode 100644
index 0000000000..d9c5462e1e
--- /dev/null
+++ b/cpukit/libdl/rtl-obj-comp.c
@@ -0,0 +1,179 @@
+/*
+ *  COPYRIGHT (c) 2012 Chris Johns <chrisj@rtems.org>
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ */
+/**
+ * @file
+ *
+ * @ingroup rtems_rtl
+ *
+ * @brief RTEMS Run-Time Linker Object Compression manages a compress
+ *        stream of data.
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <rtems/rtl/rtl-allocator.h>
+#include "rtl-obj-comp.h"
+#include "rtl-error.h"
+
+#include "fastlz.h"
+
+#include <stdio.h>
+
+bool
+rtems_rtl_obj_comp_open (rtems_rtl_obj_comp_t*  comp,
+                         size_t                 size)
+{
+  comp->cache  = NULL;
+  comp->fd = -1;
+  comp->compression = RTEMS_RTL_COMP_LZ77;
+  comp->offset = 0;
+  comp->size   = size;
+  comp->level  = 0;
+  comp->buffer = rtems_rtl_alloc_new (RTEMS_RTL_ALLOC_OBJECT, size, false);
+  if (!comp->buffer)
+  {
+    rtems_rtl_set_error (ENOMEM, "no memory for compressor buffer");
+    return false;
+  }
+  comp->read = 0;
+  return true;
+}
+
+void
+rtems_rtl_obj_comp_close (rtems_rtl_obj_comp_t* comp)
+{
+  rtems_rtl_alloc_del (RTEMS_RTL_ALLOC_OBJECT, comp->buffer);
+  comp->cache = NULL;
+  comp->fd = -1;
+  comp->compression = RTEMS_RTL_COMP_LZ77;
+  comp->level = 0;
+  comp->size = 0;
+  comp->offset = 0;
+  comp->read = 0;
+}
+
+void
+rtems_rtl_obj_comp_set (rtems_rtl_obj_comp_t*  comp,
+                        rtems_rtl_obj_cache_t* cache,
+                        int                    fd,
+                        int                    compression,
+                        off_t                  offset)
+{
+  comp->cache = cache;
+  comp->fd = fd;
+  comp->compression = compression;
+  comp->offset = offset;
+  comp->level = 0;
+  comp->read = 0;
+}
+
+bool
+rtems_rtl_obj_comp_read (rtems_rtl_obj_comp_t* comp,
+                         void*                 buffer,
+                         size_t                length)
+{
+  uint8_t* bin = buffer;
+
+  if (!comp->cache)
+  {
+    rtems_rtl_set_error (EINVAL, "not open");
+    return false;
+  }
+
+  if (comp->fd != comp->cache->fd)
+  {
+    comp->level = 0;
+  }
+
+  while (length)
+  {
+    size_t buffer_level;
+
+    buffer_level = length > comp->level ? comp->level : length;
+
+    if (buffer_level)
+    {
+      memcpy (bin, comp->buffer, buffer_level);
+
+      if ((comp->level - buffer_level) != 0)
+      {
+        memmove (comp->buffer,
+                 comp->buffer + buffer_level,
+                 comp->level - buffer_level);
+      }
+
+      bin += buffer_level;
+      length -= buffer_level;
+      comp->level -= buffer_level;
+      comp->read += buffer_level;
+    }
+
+    if (length)
+    {
+      uint8_t* input = NULL;
+      uint16_t block_size;
+      size_t   in_length = sizeof (block_size);
+      int      decompressed;
+
+      if (!rtems_rtl_obj_cache_read (comp->cache, comp->fd, comp->offset,
+                                     (void**) &input, &in_length))
+        return false;
+
+      block_size = (input[0] << 8) | input[1];
+
+      comp->offset += sizeof (block_size);
+
+      in_length = block_size;
+
+      if (!rtems_rtl_obj_cache_read (comp->cache, comp->fd, comp->offset,
+                                     (void**) &input, &in_length))
+        return false;
+
+      if (in_length != block_size)
+      {
+        rtems_rtl_set_error (EIO, "compressed read failed: bs=%u in=%u",
+                             block_size, in_length);
+        return false;
+      }
+
+      switch (comp->compression)
+      {
+        case RTEMS_RTL_COMP_NONE:
+          memcpy (comp->buffer, input, in_length);
+          decompressed = in_length;
+          break;
+
+        case RTEMS_RTL_COMP_LZ77:
+          decompressed = fastlz_decompress (input, in_length,
+                                            comp->buffer, comp->size);
+          if (decompressed == 0)
+          {
+            rtems_rtl_set_error (EBADF, "decompression failed");
+            return false;
+          }
+          break;
+
+        default:
+          rtems_rtl_set_error (EINVAL, "bad compression type");
+          return false;
+      }
+
+      comp->offset += block_size;
+
+      comp->level = decompressed;
+    }
+  }
+
+  return true;
+}