Files
UnHided/mediaflow_proxy/utils/hls_prebuffer.py
UrloMythus 7785e8c604 new version
2026-01-11 14:29:22 +01:00

490 lines
22 KiB
Python

import asyncio
import logging
import psutil
from typing import Dict, Optional, List
from urllib.parse import urlparse
import httpx
from mediaflow_proxy.utils.http_utils import create_httpx_client
from mediaflow_proxy.configs import settings
from collections import OrderedDict
import time
from urllib.parse import urljoin
logger = logging.getLogger(__name__)
class HLSPreBuffer:
"""
Pre-buffer system for HLS streams to reduce latency and improve streaming performance.
"""
def __init__(self, max_cache_size: Optional[int] = None, prebuffer_segments: Optional[int] = None):
"""
Initialize the HLS pre-buffer system.
Args:
max_cache_size (int): Maximum number of segments to cache (uses config if None)
prebuffer_segments (int): Number of segments to pre-buffer ahead (uses config if None)
"""
from collections import OrderedDict
import time
from urllib.parse import urljoin
self.max_cache_size = max_cache_size or settings.hls_prebuffer_cache_size
self.prebuffer_segments = prebuffer_segments or settings.hls_prebuffer_segments
self.max_memory_percent = settings.hls_prebuffer_max_memory_percent
self.emergency_threshold = settings.hls_prebuffer_emergency_threshold
# Cache LRU
self.segment_cache: "OrderedDict[str, bytes]" = OrderedDict()
# Mappa playlist -> lista segmenti
self.segment_urls: Dict[str, List[str]] = {}
# Mappa inversa segmento -> (playlist_url, index)
self.segment_to_playlist: Dict[str, tuple[str, int]] = {}
# Stato per playlist: {headers, last_access, refresh_task, target_duration}
self.playlist_state: Dict[str, dict] = {}
self.client = create_httpx_client()
async def prebuffer_playlist(self, playlist_url: str, headers: Dict[str, str]) -> None:
"""
Pre-buffer segments from an HLS playlist.
Args:
playlist_url (str): URL of the HLS playlist
headers (Dict[str, str]): Headers to use for requests
"""
try:
logger.debug(f"Starting pre-buffer for playlist: {playlist_url}")
response = await self.client.get(playlist_url, headers=headers)
response.raise_for_status()
playlist_content = response.text
# Se master playlist: prendi la prima variante (fix relativo)
if "#EXT-X-STREAM-INF" in playlist_content:
logger.debug(f"Master playlist detected, finding first variant")
variant_urls = self._extract_variant_urls(playlist_content, playlist_url)
if variant_urls:
first_variant_url = variant_urls[0]
logger.debug(f"Pre-buffering first variant: {first_variant_url}")
await self.prebuffer_playlist(first_variant_url, headers)
else:
logger.warning("No variants found in master playlist")
return
# Media playlist: estrai segmenti, salva stato e lancia refresh loop
segment_urls = self._extract_segment_urls(playlist_content, playlist_url)
self.segment_urls[playlist_url] = segment_urls
# aggiorna mappa inversa
for idx, u in enumerate(segment_urls):
self.segment_to_playlist[u] = (playlist_url, idx)
# prebuffer iniziale
await self._prebuffer_segments(segment_urls[:self.prebuffer_segments], headers)
logger.info(f"Pre-buffered {min(self.prebuffer_segments, len(segment_urls))} segments for {playlist_url}")
# setup refresh loop se non già attivo
target_duration = self._parse_target_duration(playlist_content) or 6
st = self.playlist_state.get(playlist_url, {})
if not st.get("refresh_task") or st["refresh_task"].done():
task = asyncio.create_task(self._refresh_playlist_loop(playlist_url, headers, target_duration))
self.playlist_state[playlist_url] = {
"headers": headers,
"last_access": asyncio.get_event_loop().time(),
"refresh_task": task,
"target_duration": target_duration,
}
except Exception as e:
logger.warning(f"Failed to pre-buffer playlist {playlist_url}: {e}")
def _extract_segment_urls(self, playlist_content: str, base_url: str) -> List[str]:
"""
Extract segment URLs from HLS playlist content.
Args:
playlist_content (str): Content of the HLS playlist
base_url (str): Base URL for resolving relative URLs
Returns:
List[str]: List of segment URLs
"""
segment_urls = []
lines = playlist_content.split('\n')
logger.debug(f"Analyzing playlist with {len(lines)} lines")
for line in lines:
line = line.strip()
if line and not line.startswith('#'):
# Check if line contains a URL (http/https) or is a relative path
if 'http://' in line or 'https://' in line:
segment_urls.append(line)
logger.debug(f"Found absolute URL: {line}")
elif line and not line.startswith('#'):
# This might be a relative path to a segment
parsed_base = urlparse(base_url)
# Ensure proper path joining
if line.startswith('/'):
segment_url = f"{parsed_base.scheme}://{parsed_base.netloc}{line}"
else:
# Get the directory path from base_url
base_path = parsed_base.path.rsplit('/', 1)[0] if '/' in parsed_base.path else ''
segment_url = f"{parsed_base.scheme}://{parsed_base.netloc}{base_path}/{line}"
segment_urls.append(segment_url)
logger.debug(f"Found relative path: {line} -> {segment_url}")
logger.debug(f"Extracted {len(segment_urls)} segment URLs from playlist")
if segment_urls:
logger.debug(f"First segment URL: {segment_urls[0]}")
else:
logger.debug("No segment URLs found in playlist")
# Log first few lines for debugging
for i, line in enumerate(lines[:10]):
logger.debug(f"Line {i}: {line}")
return segment_urls
def _extract_variant_urls(self, playlist_content: str, base_url: str) -> List[str]:
"""
Estrae le varianti dal master playlist. Corretto per gestire URI relativi:
prende la riga non-commento successiva a #EXT-X-STREAM-INF e la risolve rispetto a base_url.
"""
from urllib.parse import urljoin
variant_urls = []
lines = [l.strip() for l in playlist_content.split('\n')]
take_next_uri = False
for line in lines:
if line.startswith("#EXT-X-STREAM-INF"):
take_next_uri = True
continue
if take_next_uri:
take_next_uri = False
if line and not line.startswith('#'):
variant_urls.append(urljoin(base_url, line))
logger.debug(f"Extracted {len(variant_urls)} variant URLs from master playlist")
if variant_urls:
logger.debug(f"First variant URL: {variant_urls[0]}")
return variant_urls
async def _prebuffer_segments(self, segment_urls: List[str], headers: Dict[str, str]) -> None:
"""
Pre-buffer specific segments.
Args:
segment_urls (List[str]): List of segment URLs to pre-buffer
headers (Dict[str, str]): Headers to use for requests
"""
tasks = []
for url in segment_urls:
if url not in self.segment_cache:
tasks.append(self._download_segment(url, headers))
if tasks:
await asyncio.gather(*tasks, return_exceptions=True)
def _get_memory_usage_percent(self) -> float:
"""
Get current memory usage percentage.
Returns:
float: Memory usage percentage
"""
try:
memory = psutil.virtual_memory()
return memory.percent
except Exception as e:
logger.warning(f"Failed to get memory usage: {e}")
return 0.0
def _check_memory_threshold(self) -> bool:
"""
Check if memory usage exceeds the emergency threshold.
Returns:
bool: True if emergency cleanup is needed
"""
memory_percent = self._get_memory_usage_percent()
return memory_percent > self.emergency_threshold
def _emergency_cache_cleanup(self) -> None:
"""
Esegue cleanup LRU rimuovendo il 50% più vecchio.
"""
if self._check_memory_threshold():
logger.warning("Emergency cache cleanup triggered due to high memory usage")
to_remove = max(1, len(self.segment_cache) // 2)
removed = 0
while removed < to_remove and self.segment_cache:
self.segment_cache.popitem(last=False) # rimuovi LRU
removed += 1
logger.info(f"Emergency cleanup removed {removed} segments from cache")
async def _download_segment(self, segment_url: str, headers: Dict[str, str]) -> None:
"""
Download a single segment and cache it.
Args:
segment_url (str): URL of the segment to download
headers (Dict[str, str]): Headers to use for request
"""
try:
memory_percent = self._get_memory_usage_percent()
if memory_percent > self.max_memory_percent:
logger.warning(f"Memory usage {memory_percent}% exceeds limit {self.max_memory_percent}%, skipping download")
return
response = await self.client.get(segment_url, headers=headers)
response.raise_for_status()
# Cache LRU
self.segment_cache[segment_url] = response.content
self.segment_cache.move_to_end(segment_url, last=True)
if self._check_memory_threshold():
self._emergency_cache_cleanup()
elif len(self.segment_cache) > self.max_cache_size:
# Evict LRU finché non rientra
while len(self.segment_cache) > self.max_cache_size:
self.segment_cache.popitem(last=False)
logger.debug(f"Cached segment: {segment_url}")
except Exception as e:
logger.warning(f"Failed to download segment {segment_url}: {e}")
async def get_segment(self, segment_url: str, headers: Dict[str, str]) -> Optional[bytes]:
"""
Get a segment from cache or download it.
Args:
segment_url (str): URL of the segment
headers (Dict[str, str]): Headers to use for request
Returns:
Optional[bytes]: Cached segment data or None if not available
"""
# Check cache first
if segment_url in self.segment_cache:
logger.debug(f"Cache hit for segment: {segment_url}")
# LRU touch
data = self.segment_cache[segment_url]
self.segment_cache.move_to_end(segment_url, last=True)
# aggiorna last_access per la playlist se mappata
pl = self.segment_to_playlist.get(segment_url)
if pl:
st = self.playlist_state.get(pl[0])
if st:
st["last_access"] = asyncio.get_event_loop().time()
return data
memory_percent = self._get_memory_usage_percent()
if memory_percent > self.max_memory_percent:
logger.warning(f"Memory usage {memory_percent}% exceeds limit {self.max_memory_percent}%, skipping download")
return None
try:
response = await self.client.get(segment_url, headers=headers)
response.raise_for_status()
segment_data = response.content
# Cache LRU
self.segment_cache[segment_url] = segment_data
self.segment_cache.move_to_end(segment_url, last=True)
if self._check_memory_threshold():
self._emergency_cache_cleanup()
elif len(self.segment_cache) > self.max_cache_size:
while len(self.segment_cache) > self.max_cache_size:
self.segment_cache.popitem(last=False)
# aggiorna last_access per playlist
pl = self.segment_to_playlist.get(segment_url)
if pl:
st = self.playlist_state.get(pl[0])
if st:
st["last_access"] = asyncio.get_event_loop().time()
logger.debug(f"Downloaded and cached segment: {segment_url}")
return segment_data
except Exception as e:
logger.warning(f"Failed to get segment {segment_url}: {e}")
return None
async def prebuffer_from_segment(self, segment_url: str, headers: Dict[str, str]) -> None:
"""
Dato un URL di segmento, prebuffer i successivi in base alla playlist e all'indice mappato.
"""
mapped = self.segment_to_playlist.get(segment_url)
if not mapped:
return
playlist_url, idx = mapped
# aggiorna access time
st = self.playlist_state.get(playlist_url)
if st:
st["last_access"] = asyncio.get_event_loop().time()
await self.prebuffer_next_segments(playlist_url, idx, headers)
async def prebuffer_next_segments(self, playlist_url: str, current_segment_index: int, headers: Dict[str, str]) -> None:
"""
Pre-buffer next segments based on current playback position.
Args:
playlist_url (str): URL of the playlist
current_segment_index (int): Index of current segment
headers (Dict[str, str]): Headers to use for requests
"""
if playlist_url not in self.segment_urls:
return
segment_urls = self.segment_urls[playlist_url]
next_segments = segment_urls[current_segment_index + 1:current_segment_index + 1 + self.prebuffer_segments]
if next_segments:
await self._prebuffer_segments(next_segments, headers)
def clear_cache(self) -> None:
"""Clear the segment cache."""
self.segment_cache.clear()
self.segment_urls.clear()
self.segment_to_playlist.clear()
self.playlist_state.clear()
logger.info("HLS pre-buffer cache cleared")
async def close(self) -> None:
"""Close the pre-buffer system."""
await self.client.aclose()
# Global pre-buffer instance
hls_prebuffer = HLSPreBuffer()
class HLSPreBuffer:
def _parse_target_duration(self, playlist_content: str) -> Optional[int]:
"""
Parse EXT-X-TARGETDURATION from a media playlist and return duration in seconds.
Returns None if not present or unparsable.
"""
for line in playlist_content.splitlines():
line = line.strip()
if line.startswith("#EXT-X-TARGETDURATION:"):
try:
value = line.split(":", 1)[1].strip()
return int(float(value))
except Exception:
return None
return None
async def _refresh_playlist_loop(self, playlist_url: str, headers: Dict[str, str], target_duration: int) -> None:
"""
Aggiorna periodicamente la playlist per seguire la sliding window e mantenere la cache coerente.
Interrompe e pulisce dopo inattività prolungata.
"""
sleep_s = max(2, min(15, int(target_duration)))
inactivity_timeout = 600 # 10 minuti
while True:
try:
st = self.playlist_state.get(playlist_url)
now = asyncio.get_event_loop().time()
if not st:
return
if now - st.get("last_access", now) > inactivity_timeout:
# cleanup specifico della playlist
urls = set(self.segment_urls.get(playlist_url, []))
if urls:
# rimuovi dalla cache solo i segmenti di questa playlist
for u in list(self.segment_cache.keys()):
if u in urls:
self.segment_cache.pop(u, None)
# rimuovi mapping
for u in urls:
self.segment_to_playlist.pop(u, None)
self.segment_urls.pop(playlist_url, None)
self.playlist_state.pop(playlist_url, None)
logger.info(f"Stopped HLS prebuffer for inactive playlist: {playlist_url}")
return
# refresh manifest
resp = await self.client.get(playlist_url, headers=headers)
resp.raise_for_status()
content = resp.text
new_target = self._parse_target_duration(content)
if new_target:
sleep_s = max(2, min(15, int(new_target)))
new_urls = self._extract_segment_urls(content, playlist_url)
if new_urls:
self.segment_urls[playlist_url] = new_urls
# rebuild reverse map per gli ultimi N (limita la memoria)
for idx, u in enumerate(new_urls[-(self.max_cache_size * 2):]):
# rimappiando sovrascrivi eventuali entry
real_idx = len(new_urls) - (self.max_cache_size * 2) + idx if len(new_urls) > (self.max_cache_size * 2) else idx
self.segment_to_playlist[u] = (playlist_url, real_idx)
# tenta un prebuffer proattivo: se conosciamo l'ultimo segmento accessibile, anticipa i successivi
# Non conosciamo l'indice di riproduzione corrente qui, quindi non facciamo nulla di aggressivo.
except Exception as e:
logger.debug(f"Playlist refresh error for {playlist_url}: {e}")
await asyncio.sleep(sleep_s)
def _extract_segment_urls(self, playlist_content: str, base_url: str) -> List[str]:
"""
Extract segment URLs from HLS playlist content.
Args:
playlist_content (str): Content of the HLS playlist
base_url (str): Base URL for resolving relative URLs
Returns:
List[str]: List of segment URLs
"""
segment_urls = []
lines = playlist_content.split('\n')
logger.debug(f"Analyzing playlist with {len(lines)} lines")
for line in lines:
line = line.strip()
if line and not line.startswith('#'):
# Check if line contains a URL (http/https) or is a relative path
if 'http://' in line or 'https://' in line:
segment_urls.append(line)
logger.debug(f"Found absolute URL: {line}")
elif line and not line.startswith('#'):
# This might be a relative path to a segment
parsed_base = urlparse(base_url)
# Ensure proper path joining
if line.startswith('/'):
segment_url = f"{parsed_base.scheme}://{parsed_base.netloc}{line}"
else:
# Get the directory path from base_url
base_path = parsed_base.path.rsplit('/', 1)[0] if '/' in parsed_base.path else ''
segment_url = f"{parsed_base.scheme}://{parsed_base.netloc}{base_path}/{line}"
segment_urls.append(segment_url)
logger.debug(f"Found relative path: {line} -> {segment_url}")
logger.debug(f"Extracted {len(segment_urls)} segment URLs from playlist")
if segment_urls:
logger.debug(f"First segment URL: {segment_urls[0]}")
else:
logger.debug("No segment URLs found in playlist")
# Log first few lines for debugging
for i, line in enumerate(lines[:10]):
logger.debug(f"Line {i}: {line}")
return segment_urls
def _extract_variant_urls(self, playlist_content: str, base_url: str) -> List[str]:
"""
Estrae le varianti dal master playlist. Corretto per gestire URI relativi:
prende la riga non-commento successiva a #EXT-X-STREAM-INF e la risolve rispetto a base_url.
"""
from urllib.parse import urljoin
variant_urls = []
lines = [l.strip() for l in playlist_content.split('\n')]
take_next_uri = False
for line in lines:
if line.startswith("#EXT-X-STREAM-INF"):
take_next_uri = True
continue
if take_next_uri:
take_next_uri = False
if line and not line.startswith('#'):
variant_urls.append(urljoin(base_url, line))
logger.debug(f"Extracted {len(variant_urls)} variant URLs from master playlist")
if variant_urls:
logger.debug(f"First variant URL: {variant_urls[0]}")
return variant_urls