Module

rendering.parsers.pygments_patch

Pygments performance patch for python-markdown.

This module provides a process-wide performance optimization that replaces Pygments' lexer lookup functions with cached versions. This avoids expensive plugin discovery on every code block during markdown rendering.

Performance Impact (826-page site):

  • Before: 86s (73% in plugin discovery)
  • After: ~29s (3× faster)

Warning:

This patch affects the global markdown.extensions.codehilite module state.
It is safe for CLI tools and single-process applications, but may not be
suitable for multi-tenant web applications.

Usage:

# One-time application (typical usage):
PygmentsPatch.apply()

# Temporary patching (for testing):
with PygmentsPatch():
    # Patch is active here
    parser.parse(content)
# Patch is removed here
View source
1 Class

Classes

PygmentsPatch
Context manager and utility class for patching Pygments lexer lookups. This patch replaces expensi…
6

Context manager and utility class for patching Pygments lexer lookups.

This patch replaces expensive Pygments plugin discovery with cached lexer instances, dramatically improving markdown parsing performance.

The patch is applied at the module level to markdown.extensions.codehilite, affecting all uses of that module in the current process.

Attributes

Name Type Description
_patched bool

Class-level flag indicating if patch is currently active
_codehilite_module ModuleType | None

Reference to the patched module (if active)
_originals dict[str, Any]

Saved original functions for restoration

Methods 3

apply classmethod
Apply the Pygments caching patch to markdown.extensions.codehilite. This metho…
0 bool 
def apply(cls) -> bool

Apply the Pygments caching patch to markdown.extensions.codehilite.

This method is idempotent - calling it multiple times is safe.

Returns

bool —

bool: True if patch was applied, False if already applied or failed.

restore classmethod
Restore the original Pygments functions. This removes the patch and restores t…
0 bool 
def restore(cls) -> bool

Restore the original Pygments functions.

This removes the patch and restores the original behavior. Primarily useful for testing.

Returns

bool —

bool: True if patch was restored, False if not currently patched.

is_patched classmethod
Check if the patch is currently active.
0 bool 
def is_patched(cls) -> bool

Check if the patch is currently active.

Returns

bool —

bool: True if patched, False otherwise.

Internal Methods 3
__init__
Initialize the patch context manager.
0 None 
def __init__(self) -> None

Initialize the patch context manager.

__enter__
Apply the patch on context enter.
0 PygmentsPatch 
def __enter__(self) -> PygmentsPatch

Apply the patch on context enter.

Returns

PygmentsPatch

__exit__
Remove the patch on context exit.
0 None 
def __exit__(self, *args: Any) -> None

Remove the patch on context exit.