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Ngx_http_output_filter

As explained in Refactoring to Rust

ngx_http_output_filter is an NGINX API function that passes a request and buffer chain to HTTP output processing for transmission to a client.

ngx_http_output_filter passes an NGINX request and an ngx_chain_t buffer chain into HTTP output processing, sending the response data to the client. section 4.6

A response-writing path typically:

  • Allocates and fills an ngx_buf_t with response bytes. section 4.6
  • Places the buffer into an ngx_chain_t whose next pointer is null for a single-buffer response. section 4.6

Calculator response

After evaluating a request body, a Rust NGINX handler formats the result, calls write_response, and uses ngx_http_output_filter to deliver the HTTP response.

How Refactoring to Rust covers it

How deep it goes
Explains request and chain arguments, buffer preparation, invocation, and failure handling, but defers deeper filter internals.
Examples
Uses a Rust calculator handler that returns an evaluated request body through a single response buffer.
What it assumes
Assumes familiarity with NGINX request handlers, response headers, buffers, pointer operations, and unsafe Rust FFI.
What you can do after
Build it from scratch by preparing headers and buffers, chaining them, and submitting the chain from a Rust NGINX handler.
How it connects
Connects ngx_http_request_t, ngx_chain_t, ngx_buf_t, and ngx_http_send_header in a response-writing pipeline.
Cover of Refactoring to Rust
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Related concepts

This explainer was generated by Manning's knowledge graph from the text of Refactoring to Rust. The section links point to the parts of the book it draws on.