https://github.com/python/cpython/commit/11378e1c859d5601bb08a43ec1c8902bf2428c90
commit: 11378e1c859d5601bb08a43ec1c8902bf2428c90
branch: 3.14
author: Miss Islington (bot) <31488909+miss-isling...@users.noreply.github.com>
committer: ambv <luk...@langa.pl>
date: 2025-07-21T18:04:13+02:00
summary:
[3.14] gh-135621: Simplify TermInfo (GH-136916) (#136925)
files:
M Lib/_pyrepl/terminfo.py
diff --git a/Lib/_pyrepl/terminfo.py b/Lib/_pyrepl/terminfo.py
index 063a285bb9900c..d02ef69cce0bd8 100644
--- a/Lib/_pyrepl/terminfo.py
+++ b/Lib/_pyrepl/terminfo.py
@@ -71,7 +71,6 @@
"OTGV", "OTGC","meml", "memu", "box1"
)
# fmt: on
-_STRING_CAPABILITY_NAMES = {name: i for i, name in enumerate(_STRING_NAMES)}
def _get_terminfo_dirs() -> list[Path]:
@@ -322,10 +321,6 @@ class TermInfo:
terminal_name: str | bytes | None
fallback: bool = True
- _names: list[str] = field(default_factory=list)
- _booleans: list[int] = field(default_factory=list)
- _numbers: list[int] = field(default_factory=list)
- _strings: list[bytes | None] = field(default_factory=list)
_capabilities: dict[str, bytes] = field(default_factory=dict)
def __post_init__(self) -> None:
@@ -362,9 +357,12 @@ def __post_init__(self) -> None:
def _parse_terminfo_file(self, terminal_name: str) -> None:
"""Parse a terminfo file.
+ Populate the _capabilities dict for easy retrieval
+
Based on ncurses implementation in:
- ncurses/tinfo/read_entry.c:_nc_read_termtype()
- ncurses/tinfo/read_entry.c:_nc_read_file_entry()
+ - ncurses/tinfo/lib_ti.c:tigetstr()
"""
data = _read_terminfo_file(terminal_name)
too_short = f"TermInfo file for {terminal_name!r} too short"
@@ -377,53 +375,36 @@ def _parse_terminfo_file(self, terminal_name: str) ->
None:
)
if magic == MAGIC16:
- number_format = "<h" # 16-bit signed
number_size = 2
elif magic == MAGIC32:
- number_format = "<i" # 32-bit signed
number_size = 4
else:
raise ValueError(
f"TermInfo file for {terminal_name!r} uses unknown magic"
)
- # Read terminal names
- if offset + name_size > len(data):
- raise ValueError(too_short)
- names = data[offset : offset + name_size - 1].decode(
- "ascii", errors="ignore"
- )
+ # Skip data than PyREPL doesn't need:
+ # - names (`|`-separated ASCII strings)
+ # - boolean capabilities (bytes with value 0 or 1)
+ # - numbers (little-endian integers, `number_size` bytes each)
offset += name_size
-
- # Read boolean capabilities
- if offset + bool_count > len(data):
- raise ValueError(too_short)
- booleans = list(data[offset : offset + bool_count])
offset += bool_count
-
- # Align to even byte boundary for numbers
if offset % 2:
+ # Align to even byte boundary for numbers
offset += 1
-
- # Read numeric capabilities
- numbers = []
- for i in range(num_count):
- if offset + number_size > len(data):
- raise ValueError(too_short)
- num = struct.unpack(
- number_format, data[offset : offset + number_size]
- )[0]
- numbers.append(num)
- offset += number_size
+ offset += num_count * number_size
+ if offset > len(data):
+ raise ValueError(too_short)
# Read string offsets
- string_offsets = []
- for i in range(str_count):
- if offset + 2 > len(data):
- raise ValueError(too_short)
- off = struct.unpack("<h", data[offset : offset + 2])[0]
- string_offsets.append(off)
- offset += 2
+ end_offset = offset + 2 * str_count
+ if offset > len(data):
+ raise ValueError(too_short)
+ string_offset_data = data[offset:end_offset]
+ string_offsets = [
+ off for [off] in struct.iter_unpack("<h", string_offset_data)
+ ]
+ offset = end_offset
# Read string table
if offset + str_size > len(data):
@@ -431,53 +412,30 @@ def _parse_terminfo_file(self, terminal_name: str) ->
None:
string_table = data[offset : offset + str_size]
# Extract strings from string table
- strings: list[bytes | None] = []
- for off in string_offsets:
+ capabilities = {}
+ for cap, off in zip(_STRING_NAMES, string_offsets):
if off < 0:
- strings.append(CANCELLED_STRING)
+ # CANCELLED_STRING; we do not store those
+ continue
elif off < len(string_table):
# Find null terminator
- end = off
- while end < len(string_table) and string_table[end] != 0:
- end += 1
- if end <= len(string_table):
- strings.append(string_table[off:end])
- else:
- strings.append(ABSENT_STRING)
- else:
- strings.append(ABSENT_STRING)
-
- self._names = names.split("|")
- self._booleans = booleans
- self._numbers = numbers
- self._strings = strings
+ end = string_table.find(0, off)
+ if end >= 0:
+ capabilities[cap] = string_table[off:end]
+ # in other cases this is ABSENT_STRING; we don't store those.
- def get(self, cap: str) -> bytes | None:
- """Get terminal capability string by name.
+ # Note: we don't support extended capabilities since PyREPL doesn't
+ # need them.
- Based on ncurses implementation in:
- - ncurses/tinfo/lib_ti.c:tigetstr()
+ self._capabilities = capabilities
- The ncurses version searches through compiled terminfo data structures.
- This version first checks parsed terminfo data, then falls back to
- hardcoded capabilities.
+ def get(self, cap: str) -> bytes | None:
+ """Get terminal capability string by name.
"""
if not isinstance(cap, str):
raise TypeError(f"`cap` must be a string, not {type(cap)}")
- if self._capabilities:
- # Fallbacks populated, use them
- return self._capabilities.get(cap)
-
- # Look up in standard capabilities first
- if cap in _STRING_CAPABILITY_NAMES:
- index = _STRING_CAPABILITY_NAMES[cap]
- if index < len(self._strings):
- return self._strings[index]
-
- # Note: we don't support extended capabilities since PyREPL doesn't
- # need them.
- return None
+ return self._capabilities.get(cap)
def tparm(cap_bytes: bytes, *params: int) -> bytes:
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