README.md in httpthumbnailer-0.3.1 vs README.md in httpthumbnailer-1.0.0

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+ new

@@ -1,101 +1,231 @@ -# httpthumbnailer +# HTTP Thumbnailer HTTP API server for image thumbnailing and format conversion. -It is using **ImageMagick** as the image processing library. +It is using [ImageMagick](http://www.imagemagick.org) or [GraphicsMagick](http://www.graphicsmagick.org) via [RMagick](http://rmagick.rubyforge.org) gem as the image processing library. +## Features + +* thumbnailing images with different aspect ratio keeping methods +* support of many input and output formats +* efficient API for generating multiple thumbnails from single input image with just one request +* many image scaling and loading performance optimizations +* efficient memory usage +* memory limits and disk memory offloading support +* based on [Unicorn HTTP server](http://unicorn.bogomips.org) with UNIX socket communication support + ## Installing -You will need the following system packages installed: `imagemagick`, `libpng`, `pkg-config`, `make`. -Optionally you may want to install `fcgi` package and gem to be able to use it as **FastCGI** backend. +You will need the following system packages installed: `imagemagick`, `pkg-config` and `make`. +For PNG support install `libpng`. You may want to consult [ImageMagick](http://www.imagemagick.org) installation guide for more information on supported formats and required libraries. For Arch Linux you can use this commands: - pacman -S imagemagick - pacman -S libpng - pacman -S pkg-config - pacman -S make +```bash +pacman -S imagemagick +pacman -S libpng +pacman -S pkg-config +pacman -S make +``` Then you can install the gem as usual: - gem install httpthumbnailer +```bash +gem install httpthumbnailer +``` +Optionally install Ruby client library and tool: + +```bash +gem install httpthumbnailer-client +``` + ## Usage -It can be started as a stand alone server or as FastCGI backend. +### Getting started -### Stand alone server +```bash +# install httpthumbnailer (see above) +# install httpthumbnailer-client +gem install httpthumbnailer-client -This mode is useful for testing. -By default **Mongrel** will be used as HTTP handling library (you can use --server option to specify different server that is supported by Sinatra). +# start thumbnailing server in foreground (to stop hit Ctlr-C) +httpthumbnailer --foreground --verbose -To start it in that mode run: +# in another console thumbnail to standard output +cat ~/Pictures/compute.jpg | httpthumbnailer-client -t crop,100,200,png > thumbnail.png - httpthumbnailer +# generate multiple thumbnails +cat ~/Pictures/compute.jpg | httpthumbnailer-client -t crop,100,200,jpeg,quality:100 -t pad,200,200,png thumbnail1.jpg thumbnail2.png +``` -By default it will be listening on **localhost** port **3100**. +In this example we use [httpthumbnailer-client](http://github.com/jpastuszek/httpthumbnailer-client) gem CLI tool that will use HTTP API of the server to generate thumbnails. -### FastCGI +### Running the server -In this mode you can run many **httpthumbnailer** instances so that requests will be load balanced between them equally. -Since it is single threaded (some ImageMagick operations may be multithreaded) it will be able to max out only single CPU core. -Therefore it is recommended to run as many instances as there are CPU cores available. +HTTP Thumbnailer uses worker based server model thanks to [Unicorn HTTP server](http://unicorn.bogomips.org) gem. -Make sure you have FastCGI system library installed. +To start the thumbnailer use `httpthumbnailer` command. +By default it will start in background and will spawn CPU core number + 1 number of worker processes. +It will be listening on **localhost** port **3100**. -For Arch Linux you can use this command: +To start in foreground with verbose output use `httpthumbnailer --verbose --foreground`. +To see available switches and options use `httpthumbnailer --help`. - pacman -S fcgi +When running in background the master server process will store it's PID in `httpthumbnailer.pid` file. You can change pid file location with `--pid-file` option. +If running as root you can use `--user` option to specify user with whose privileges the worker processes will be running. -And you have `fcgi` gem installed with: +### Logging - gem install fcgi +`httpthumbnailer` logs to `httpthumbnailer.log` file in current directory by default. You can change log file location with `--log-file` option and verbosity with `--verbose` or `--debug` switch. -Here is an example **Lighttpd** configuration: +Additionally `httpthumbnailer` will log requests in [common NCSA format](http://en.wikipedia.org/wiki/Common_Log_Format) to `httpthumbnailer_access.log` file. Use `--access-log-file` option to change location of access log. - $SERVER["socket"] == ":3100" { - server.reject-expect-100-with-417 = "disable" - fastcgi.debug = 1 - fastcgi.server = ( "/" => - (( - "socket" => "/var/run/lighttpd/httpthumbniler.sock", - "bin-path" => "/usr/bin/httpthumbnailer -s fastcgi --no-bind --no-logging", - "max-procs" => 2, - "check-local" => "disable", - "fix-root-scriptname" => "enable", - )) - ) - } +### Supported operations -The `"max-procs" => 2` controls the number of instances started. -In case that the `httpthumbnailer` process crashes (may happen since it is using native libraries) it will be restarted by Lighttpd. +As operation type you can select one of the following options: +* fit - fit image within given dimensions keeping aspect ratio +* crop - cut image to fit within given dimensions keeping aspect ratio +* pad - fit scale image and pad image with background colour to given dimensions keeping aspect ratio +* limit - fit scale image to given dimensions if it is larger than that dimensions +### Supported formats + +List of supported formats can be displayed with `httpthumbnailer --formats`. +Optionally format `input` can be used to use the same thumbnail format as input image. + +### Thumbnail width and height + +Width and height values are interpreted depending on operation. +`input` string can be used for width and/or height to use input image width or height. + +### Thumbnail options + +Following options can be used with thumbnail specification: +* quality - set output image quality; this is format specific: for JPEG 0 is maximum compression and 100 is maximum quality, for PNG first digit is zlib compression level and second one is filter level +* background-color - color in HTML notation or textual description ('red', 'green' etc.) used for background when processing transparent images or padding; by default white background is used + ### API -Basically it works like that: +#### Single thumbnail API -1. PUT your image data to the server with URI describing thumbnail format (one or more) -2. the server will respond with **multi-part content** with parts containing data of your thumbnails in order with proper **Content-type** headers set +To generate single thumbnail send input image with **PUT** request to URI in format: + /thumbnail/<operation type>,<width>,<height>,<format>[,<option key>:<option value>]* + +Server will respond with thumbnail data with correct **Content-Type** header value. + For example the URI may look like this: - /thumbnail/crop,16,16,PNG/crop,4,8,JPG/pad,16,32,JPEG + /thumbnail/pad,100,100,png,background-color:green -It will generate 3 thumbnails: +For detailed information about the API see [cucumber features](http://github.com/jpastuszek/httpthumbnailer/blob/master/features/thumbnail.feature). -1. 16x16 cropped PNG -2. 4x8 cropped JPEG -3. 16x32 colour padded JPEG +#### Multipart API -For detailed information about the API see [cucumber features](http://github.com/jpastuszek/httpthumbnailer/blob/master/features/httpthumbnailer.feature). +To generate multiple thumbnails of single image send that image with **PUT** request to URI in format: -### API client + /thumbnails/<operation type>,<width>,<height>,<format>[,<option key>:<option value>]*[/<operation type>,<width>,<height>,<format>[,<option key>:<option value>]*]* -To make it easy to use this server there is [httpthumbnailer-client](http://github.com/jpastuszek/httpthumbnailer-client) gem provided. +Server will respond with **multi-part content** with each part containing **Content-Type** header and thumbnail data corresponding to format defined in the URI. -## Contributing to httpthumbnailer +For example the URI may look like this: + + /thumbnails/crop,16,16,png/crop,4,8,jpg/pad,16,32,jpeg + +HTTP Thumbnailer will generate 3 thumbnails: + 1. 16x16 cropped PNG + 2. 4x8 cropped JPEG + 3. 16x32 colour padded JPEG + +For detailed information about the API see [cucumber features](http://github.com/jpastuszek/httpthumbnailer/blob/master/features/thumbnails.feature). + +### Ruby API client + +To make it easier to use this server [httpthumbnailer-client](http://github.com/jpastuszek/httpthumbnailer-client) gem provides useful class. + +### Memory limits + +Each worker uses [ImageMagick](http://www.imagemagick.org) memory usage limit feature. +By default it will use up to 128MiB of RAM and up to 1GiB of disk backed virtual memory. +To change this defaults use `--limit-memory` option for RAM limit and `--limit-disk` to control file backed memory mapping limit in MiB. + +## Status codes + +HTTP Thumbnailer will respond with different status codes on different situations. +If all goes well 200 OK will be returned otherwise: + +### 400 + +* requested thumbnail method is not supported +* at least one image dimension is zero in thumbnail spec +* missing option key or value in thumbnail spec +* missing argument in in thumbnail spec +* bad argument value + +### 413 + +* request body is too long +* input image is too big to fit in memory +* memory or pixel cache limit has been exceeded + +### 415 + +* unsupported media type - see **Supported formats** section + +### 500 + +* unexpected error has occurred - see the log file + +### Multipart API + +In multipart API when error relates to single thumbnail `Content-Type: plain/text` header will be used for that part. +In addition `Status` header will be set for failing part with number corresponding to above status codes. +The body will contain description of the error. + +## Statistics API + +HTTP Thumbnailer comes with statistics API that shows various runtime collected statistics. +It is set up under `/stats` URI. You can also request single stat with `/stats/<stat name>` request. + +Example: + +```bash +$ curl 127.0.0.1:3100/stats +total_requests: 119 +total_errors: 1 +calling: 1 +writing: 0 +total_images_loaded: 115 +total_images_prescaled: 30 +total_thumbnails_created: 147 +images_loaded: 0 +max_images_loaded: 3 +max_images_loaded_worker: 3 +total_images_created: 312 +total_images_destroyed: 312 +total_images_created_from_blob: 115 +total_images_created_initialize: 53 +total_images_created_resize: 101 +total_images_created_crop: 13 +total_images_created_sample: 30 +total_write_multipart: 16 +total_write: 101 +total_write_part: 48 +total_write_error: 1 +total_write_error_part: 0 + +$ curl 127.0.0.1:3100/stats/total_write_multipart +16 +``` + +## See also + +[HTTP Image Store](https://github.com/jpastuszek/httpimagestore) service is configurable image storage and processing HTTP API server that uses this service as thumbnailing backend. + +## Contributing to HTTP Thumbnailer * Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet * Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it * Fork the project * Start a feature/bugfix branch @@ -103,8 +233,8 @@ * Make sure to add tests for it. This is important so I don't break it in a future version unintentionally. * Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it. ## Copyright -Copyright (c) 2012 Jakub Pastuszek. See LICENSE.txt for +Copyright (c) 2013 Jakub Pastuszek. See LICENSE.txt for further details.