tools (common/utils): new methods to parse and generate file size with symbols:

- `parseSize` lets parse a size which can be either a int, or a string with a symbol like
  `Mio`
- `getSizeMultiplier` returns a tuple of size with it's multiplier symbol
- `getHumanSize` returns a string with size and adapted multiplier.

sat/tools/common/utils.py

@@ -19,6 +19,42 @@
 """Misc utils for both backend and frontends"""
 
 import collections.abc
+size_units = {
+    "b": 1,
+    "kb": 1000,
+    "mb": 1000**2,
+    "gb": 1000**3,
+    "tb": 1000**4,
+    "pb": 1000**5,
+    "eb": 1000**6,
+    "zb": 1000**7,
+    "yb": 1000**8,
+    "o": 1,
+    "ko": 1000,
+    "mo": 1000**2,
+    "go": 1000**3,
+    "to": 1000**4,
+    "po": 1000**5,
+    "eo": 1000**6,
+    "zo": 1000**7,
+    "yo": 1000**8,
+    "kib": 1024,
+    "mib": 1024**2,
+    "gib": 1024**3,
+    "tib": 1024**4,
+    "pib": 1024**5,
+    "eib": 1024**6,
+    "zib": 1024**7,
+    "yib": 1024**8,
+    "kio": 1024,
+    "mio": 1024**2,
+    "gio": 1024**3,
+    "tio": 1024**4,
+    "pio": 1024**5,
+    "eio": 1024**6,
+    "zio": 1024**7,
+    "yio": 1024**8,
+}
 
 
 def per_luminance(red, green, blue):
@@ -73,3 +109,51 @@ class OrderedSet(collections.abc.MutableSet):
 
     def update(self, items):
         self._dict.update({i: None for i in items})
+
+
+def parseSize(size):
+    """Parse a file size with optional multiple symbole"""
+    try:
+        return int(size)
+    except ValueError:
+        number = []
+        symbol = []
+        try:
+            for c in size:
+                if c == " ":
+                    continue
+                if c.isdigit():
+                    number.append(c)
+                elif c.isalpha():
+                    symbol.append(c)
+                else:
+                    raise ValueError("unexpected char in size: {c!r} (size: {size!r})")
+            number = int("".join(number))
+            symbol = "".join(symbol)
+            if symbol:
+                try:
+                    multiplier = size_units[symbol.lower()]
+                except KeyError:
+                    raise ValueError(
+                        "unknown size multiplier symbole: {symbol!r} (size: {size!r})")
+                else:
+                    return number * multiplier
+            return number
+        except Exception as e:
+            raise ValueError(f"invalid size: {e}")
+
+
+def getSizeMultiplier(size, suffix="o"):
+    """Get multiplier of a file size"""
+    size = int(size)
+    #  cf. https://stackoverflow.com/a/1094933 (thanks)
+    for unit in ["", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei", "Zi"]:
+        if abs(size) < 1024.0:
+            return size, f"{unit}{suffix}"
+        size /= 1024.0
+    return size, f"Yi{suffix}"
+
+
+def getHumanSize(size, suffix="o", sep=" "):
+    size, symbol = getSizeMultiplier(size, suffix)
+    return f"{size:.2f}{sep}{symbol}"