Image resizing service.

go build -o bin/resizer ./cmd/resizer

Usage of resizer:
  -addr string
        address to listen on (default "localhost:8080")
  -cache-origdir string
        directory for original images (default "cache/orig")
  -cache-outdir string
        directory for resized images (default "cache/output")
  -client-timeout duration
        http client timeout (default 10s)
  -request-timeout duration
        request timeout when not provided (default 30s)

Submit images for resizing.

Query params:

• async=true - returns immediately
• timeout=<seconds> - overrides default request timeout

Request:

{
  "urls": ["http://example.com/image.jpg"],
  "width": 800,
  "height": 600
}

Response (201):

[
  {
    "result": "success",
    "source": "http://example.com/image.jpg",
    "url": "http://localhost:8080/v1/image/Xj8K...Qw.800x600.jpg",
    "cached": true
  },
  {
    "result": "failure",
    "source": "http://example.com/notfoundimage.jpg",
    "reason":"HTTP 404: 404 File not found",
    "cached": false
  }
]

In blocking mode (default), waits for processing to complete, returns results when done or timeout.

In async mode (?async=true), returns results immediately, always with success.

Constraints:

• Max 100 URLs per request
• Max 1MB request body
• Max 9999×9999 dimensions
• Max 1000 chars per URL
• http/https only
• At least one dimension must be > 0
• No self-referencing URLs

Error responses: 400 (validation), 405 (method), 413 (body size), 408 (timeout)

Retrieve resized image.

Path format: {sha256_hash}.{width}x{height}.{ext}

Example: /v1/image/Xj8KLm9pQw.800x600.jpg

Query params:

• timeout=<seconds> - overrides default request timeout

Returns:

• 200 with image
• 404 if not found or not processing
• 408 if processing timeout
• 500 if processing failed

Path constraints: max 57 chars, alphanumeric/dots/hyphens/underscores only, .jpg or .png extensions.

Downloads and resizes images. Manages cache. SHA256 hashing for filenames.

Tracks processing state per hash. Per-hash mutex locks for concurrency. Notifies waiting requests on completion.

go test -v ./...