From c626bebb5979047dc5d46c39b9911fa012d6a499 Mon Sep 17 00:00:00 2001
From: Mike Auty <mike.auty@gmail.com>
Date: Sat, 2 Jul 2016 15:48:09 +0100
Subject: [PATCH] Convert mapping to a generator rather than a list. It must
 still return in sorted order.

---
 volatility/framework/interfaces/layers.py |  2 +-
 volatility/framework/layers/intel.py      | 12 ++++++------
 volatility/framework/layers/lime.py       | 12 ++++++------
 3 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/volatility/framework/interfaces/layers.py b/volatility/framework/interfaces/layers.py
index fa1710f2c..bb19251a5 100644
--- a/volatility/framework/interfaces/layers.py
+++ b/volatility/framework/interfaces/layers.py
@@ -95,7 +95,7 @@ class TranslationLayerInterface(DataLayerInterface, metaclass = ABCMeta):
 
     @abstractmethod
     def mapping(self, offset, length, ignore_errors = False):
-        """Returns a sorted list of (offset, mapped_offset, length, layer) mappings
+        """Returns a sorted iterable of (offset, mapped_offset, length, layer) mappings
 
            ignore_errors will provide all available maps with gaps, but their total length may not add up to the requested length
            This allows translation layers to provide maps of contiguous regions in one layer
diff --git a/volatility/framework/layers/intel.py b/volatility/framework/layers/intel.py
index c73bac1f9..cb1c7c597 100644
--- a/volatility/framework/layers/intel.py
+++ b/volatility/framework/layers/intel.py
@@ -109,29 +109,29 @@ class Intel(interfaces.layers.TranslationLayerInterface):
             return False
 
     def mapping(self, offset, length, ignore_errors = False):
-        """Returns a sorted list of (offset, mapped_offset, length, layer) mappings
+        """Returns a sorted iterable of (offset, mapped_offset, length, layer) mappings
 
            This allows translation layers to provide maps of contiguous regions in one layer
         """
         result = []
         if length == 0:
             if ignore_errors and not self.is_valid(offset):
-                return result
+                raise StopIteration
             mapped_offset, _ = self._translate(offset)
-            return [(offset, mapped_offset, length, self._base_layer)]
+            yield (offset, mapped_offset, length, self._base_layer)
+            raise StopIteration
         while length > 0:
             if ignore_errors:
                 while not self.is_valid(offset) and length > 0:
                     length -= 1 << self._page_size_in_bits
                     offset += 1 << self._page_size_in_bits
                 if length <= 0:
-                    return result
+                    raise StopIteration
             chunk_offset, page_size = self._translate(offset)
             chunk_size = min(page_size - (chunk_offset % page_size), length)
-            result.append((offset, chunk_offset, chunk_size, self._base_layer))
+            yield (offset, chunk_offset, chunk_size, self._base_layer)
             length -= chunk_size
             offset += chunk_size
-        return result
 
     @property
     def dependencies(self):
diff --git a/volatility/framework/layers/lime.py b/volatility/framework/layers/lime.py
index e18769eb6..c569ad9b9 100644
--- a/volatility/framework/layers/lime.py
+++ b/volatility/framework/layers/lime.py
@@ -105,7 +105,7 @@ class LimeLayer(interfaces.layers.TranslationLayerInterface):
             return False
 
     def mapping(self, offset, length, ignore_errors = False):
-        """Returns a sorted list of (offset, mapped_offset, length, layer) mappings"""
+        """Returns a sorted iterable of (offset, mapped_offset, length, layer) mappings"""
         result = []
         if ignore_errors:
             for (seg_offset, mapped_seg_offset, seg_length) in self._segments:
@@ -118,20 +118,20 @@ class LimeLayer(interfaces.layers.TranslationLayerInterface):
                     seg_offset += diff
                 if offset + length < seg_offset + seg_length:
                     seg_length = offset + length - seg_offset
-                result.append((seg_offset, mapped_seg_offset, seg_length, self._base_layer))
-            return result
+                yield (seg_offset, mapped_seg_offset, seg_length, self._base_layer)
+            raise StopIteration
         if length == 0:
             logical_start, base_start, size = self._find_segment(offset)
             mapped_offset = offset - logical_start + base_start
-            return [(offset, mapped_offset, 0, self._base_layer)]
+            yield (offset, mapped_offset, 0, self._base_layer)
+            raise StopIteration
         while length > 0:
             logical_start, base_start, size = self._find_segment(offset)
             chunk_offset = offset - logical_start + base_start
             chunk_size = min(size - (offset - logical_start), length)
-            result.append((offset, chunk_offset, chunk_size, self._base_layer))
+            yield (offset, chunk_offset, chunk_size, self._base_layer)
             length -= chunk_size
             offset += chunk_size
-        return result
 
     @property
     def dependencies(self):