```mermaid
flowchart TD
A[Start channel_fetch] --> B[Create bounded channel]
B --> C[Create semaphore]
C --> D[For each entry]
D --> E[Spawn task]
E --> F[Acquire semaphore permit]
F --> G{Entry in DB?}
G -->|No| H[Fetch from URL]
G -->|Yes| I[Skip fetching]
H --> J[Send entry and bytes to channel]
I --> J
J --> K[Release semaphore permit]
K --> L{All entries processed?}
L -->|No| D
L -->|Yes| M[Process received entries]
M --> N[For each received entry]
N --> O[Handle entry]
O --> P{All entries handled?}
P -->|No| N
P -->|Yes| Q[End channel_fetch]
```
