Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Optimise ImageMode.getmode using functools.lru_cache #7641

Merged
merged 2 commits into from Dec 26, 2023
Merged

Optimise ImageMode.getmode using functools.lru_cache #7641

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
26f58e7
Optimise ImageMode.getmode
hugovk Dec 22, 2023
396b96f
Optimise ImageMode.getmode
hugovk Dec 26, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
110 changes: 54 additions & 56 deletions src/PIL/ImageMode.py
View file
Open in desktop
Expand Up @@ -15,9 +15,7 @@
from __future__ import annotations

import sys

# mode descriptor cache
_modes = None
from functools import lru_cache


class ModeDescriptor:
Expand All @@ -41,58 +39,58 @@ def __str__(self) -> str:
return self.mode


@lru_cache
def getmode(mode: str) -> ModeDescriptor:
"""Gets a mode descriptor for the given mode."""
global _modes
if not _modes:
# initialize mode cache
modes = {}
endian = "<" if sys.byteorder == "little" else ">"
for m, (basemode, basetype, bands, typestr) in {
# core modes
# Bits need to be extended to bytes
"1": ("L", "L", ("1",), "|b1"),
"L": ("L", "L", ("L",), "|u1"),
"I": ("L", "I", ("I",), endian + "i4"),
"F": ("L", "F", ("F",), endian + "f4"),
"P": ("P", "L", ("P",), "|u1"),
"RGB": ("RGB", "L", ("R", "G", "B"), "|u1"),
"RGBX": ("RGB", "L", ("R", "G", "B", "X"), "|u1"),
"RGBA": ("RGB", "L", ("R", "G", "B", "A"), "|u1"),
"CMYK": ("RGB", "L", ("C", "M", "Y", "K"), "|u1"),
"YCbCr": ("RGB", "L", ("Y", "Cb", "Cr"), "|u1"),
# UNDONE - unsigned |u1i1i1
"LAB": ("RGB", "L", ("L", "A", "B"), "|u1"),
"HSV": ("RGB", "L", ("H", "S", "V"), "|u1"),
# extra experimental modes
"RGBa": ("RGB", "L", ("R", "G", "B", "a"), "|u1"),
"BGR;15": ("RGB", "L", ("B", "G", "R"), "|u1"),
"BGR;16": ("RGB", "L", ("B", "G", "R"), "|u1"),
"BGR;24": ("RGB", "L", ("B", "G", "R"), "|u1"),
"LA": ("L", "L", ("L", "A"), "|u1"),
"La": ("L", "L", ("L", "a"), "|u1"),
"PA": ("RGB", "L", ("P", "A"), "|u1"),
}.items():
modes[m] = ModeDescriptor(m, bands, basemode, basetype, typestr)
# mapping modes
for i16mode, typestr in {
# I;16 == I;16L, and I;32 == I;32L
"I;16": "<u2",
"I;16S": "<i2",
"I;16L": "<u2",
"I;16LS": "<i2",
"I;16B": ">u2",
"I;16BS": ">i2",
"I;16N": endian + "u2",
"I;16NS": endian + "i2",
"I;32": "<u4",
"I;32B": ">u4",
"I;32L": "<u4",
"I;32S": "<i4",
"I;32BS": ">i4",
"I;32LS": "<i4",
}.items():
modes[i16mode] = ModeDescriptor(i16mode, ("I",), "L", "L", typestr)
# set global mode cache atomically
_modes = modes
return _modes[mode]
# initialize mode cache
endian = "<" if sys.byteorder == "little" else ">"

modes = {
# core modes
# Bits need to be extended to bytes
"1": ("L", "L", ("1",), "|b1"),
"L": ("L", "L", ("L",), "|u1"),
"I": ("L", "I", ("I",), endian + "i4"),
"F": ("L", "F", ("F",), endian + "f4"),
"P": ("P", "L", ("P",), "|u1"),
"RGB": ("RGB", "L", ("R", "G", "B"), "|u1"),
"RGBX": ("RGB", "L", ("R", "G", "B", "X"), "|u1"),
"RGBA": ("RGB", "L", ("R", "G", "B", "A"), "|u1"),
"CMYK": ("RGB", "L", ("C", "M", "Y", "K"), "|u1"),
"YCbCr": ("RGB", "L", ("Y", "Cb", "Cr"), "|u1"),
# UNDONE - unsigned |u1i1i1
"LAB": ("RGB", "L", ("L", "A", "B"), "|u1"),
"HSV": ("RGB", "L", ("H", "S", "V"), "|u1"),
# extra experimental modes
"RGBa": ("RGB", "L", ("R", "G", "B", "a"), "|u1"),
"BGR;15": ("RGB", "L", ("B", "G", "R"), "|u1"),
"BGR;16": ("RGB", "L", ("B", "G", "R"), "|u1"),
"BGR;24": ("RGB", "L", ("B", "G", "R"), "|u1"),
"LA": ("L", "L", ("L", "A"), "|u1"),
"La": ("L", "L", ("L", "a"), "|u1"),
"PA": ("RGB", "L", ("P", "A"), "|u1"),
}
if mode in modes:
base_mode, base_type, bands, type_str = modes[mode]
return ModeDescriptor(mode, bands, base_mode, base_type, type_str)

mapping_modes = {
# I;16 == I;16L, and I;32 == I;32L
"I;16": "<u2",
"I;16S": "<i2",
"I;16L": "<u2",
"I;16LS": "<i2",
"I;16B": ">u2",
"I;16BS": ">i2",
"I;16N": endian + "u2",
"I;16NS": endian + "i2",
"I;32": "<u4",
"I;32B": ">u4",
"I;32L": "<u4",
"I;32S": "<i4",
"I;32BS": ">i4",
"I;32LS": "<i4",
}

type_str = mapping_modes[mode]
return ModeDescriptor(mode, ("I",), "L", "L", type_str)