Added common code into fileutils and strutils.

This methods are present in nova, cinder and also needed by ironic package.

openstack.common.strutils => nova.utils <=> cinder.utils
    to_bytes(text, default=0)

openstack.common.fileutils => nova.utils <=> cinder.utils <=> nova/virt/libvirt/utils.py
    file_open(*args, **kwargs)

Change-Id: Ia65499b77eb551c0ffb6d48767b899435469bfb6
Implements: blueprint image-tools

2 files changed, 51 insertions, 0 deletions

diff --git a/openstack/common/fileutils.py b/openstack/common/fileutils.py
index 0c967da..9f8807f 100644
--- a/openstack/common/fileutils.py
+++ b/openstack/common/fileutils.py
@@ -96,3 +96,15 @@ def remove_path_on_error(path):
     except Exception:
         with excutils.save_and_reraise_exception():
             delete_if_exists(path)
+
+
+def file_open(*args, **kwargs):
+    """Open file
+
+    see built-in file() documentation for more details
+
+    Note: The reason this is kept in a separate module is to easily
+    be able to provide a stub module that doesn't alter system
+    state at all (for unit tests)
+    """
+    return file(*args, **kwargs)
diff --git a/openstack/common/strutils.py b/openstack/common/strutils.py
index 6d227c6..8a5367b 100644
--- a/openstack/common/strutils.py
+++ b/openstack/common/strutils.py
@@ -24,6 +24,17 @@ import sys
 from openstack.common.gettextutils import _
 
 
+# Used for looking up extensions of text
+# to their 'multiplied' byte amount
+BYTE_MULTIPLIERS = {
+    '': 1,
+    't': 1024 ** 4,
+    'g': 1024 ** 3,
+    'm': 1024 ** 2,
+    'k': 1024,
+}
+
+
 TRUE_STRINGS = ('1', 't', 'true', 'on', 'y', 'yes')
 FALSE_STRINGS = ('0', 'f', 'false', 'off', 'n', 'no')
 
@@ -148,3 +159,31 @@ def safe_encode(text, incoming=None,
         return text.encode(encoding, errors)
 
     return text
+
+
+def to_bytes(text, default=0):
+    """Try to turn a string into a number of bytes. Looks at the last
+    characters of the text to determine what conversion is needed to
+    turn the input text into a byte number.
+
+    Supports: B/b, K/k, M/m, G/g, T/t (or the same with b/B on the end)
+
+    """
+    # Take off everything not number 'like' (which should leave
+    # only the byte 'identifier' left)
+    mult_key_org = text.lstrip('-1234567890')
+    mult_key = mult_key_org.lower()
+    mult_key_len = len(mult_key)
+    if mult_key.endswith("b"):
+        mult_key = mult_key[0:-1]
+    try:
+        multiplier = BYTE_MULTIPLIERS[mult_key]
+        if mult_key_len:
+            # Empty cases shouldn't cause text[0:-0]
+            text = text[0:-mult_key_len]
+        return int(text) * multiplier
+    except KeyError:
+        msg = _('Unknown byte multiplier: %s') % mult_key_org
+        raise TypeError(msg)
+    except ValueError:
+        return default