Features
Download Engine
Development entry points for HTTP chunking, resume, acceleration, speed limits, and proxies.
The main HTTP download logic lives in features/http_pack. It probes Range support, file size, and filenames, then creates tasks that write directly into the target file at specific offsets.
Key Implementations
| Topic | Source Entry | Notes |
|---|---|---|
| URL probe | features/http_pack/pack.py | Detects filename, size, and Range support. |
| Chunked download | features/http_pack/task.py | Writes directly to the target file, without a merge step after completion. |
| Resume support | features/http_pack/task.py | Depends on the target file plus auxiliary progress state. |
| Auto acceleration | features/http_pack/task.py | Observes remaining chunks and reallocates them when needed. |
| Speed limits / proxies | app/supports/config.py, app/supports/utils.py | HTTP, FTP, and BT apply them differently. |
User-visible Behavior
| Behavior | Effect |
|---|---|
| Range probe fails | The task may fall back to a single connection, or resume support may not work. |
| Target file and progress state are inconsistent | Resume may fail and require cleanup or a full redownload. |
| Proxy config is invalid | HTTP, FTP, and BT fail in different ways and must be debugged separately. |
| SSL verification fails | HTTPS links may fail during parsing or download. |
| Auto acceleration reallocation | Large-file downloads may speed up, but the result still depends on server-side throttling. |