about SPF policies [here](http://www.openspf.org/). A number of mail systems includes SPF support, such as `gmail` or `yahoo mail`.
-* **DKIM module** validates message's cryptographic signature against public key placed in the DNS record of sender's domain. Like SPF,
+* **DKIM module** validates a message cryptographic signature against a public key placed in the DNS record of sender's domain. Like SPF,
this technique is widely spread and allows to validate that a message is sent from that specific domain.
* **Fuzzy hashes** - for checking of malicious mail patterns rspamd uses so called `fuzzy hashes`. Unlike normal hashes, these structures are targeted to hide
small differences between text patterns allowing to find similar messages quickly. Rspamd has internal storage of such hashes and allows to block mass spam sendings
-quickly based on user's feedback that specifies messages reputation. Moreover, it allows to feed rspamd with data from [`honeypots`](http://en.wikipedia.org/wiki/Honeypot_(computing)#Spam_versions)
+quickly based on user's feedback that specifies messages reputation. Moreover, this allows to feed rspamd with data from [`honeypots`](http://en.wikipedia.org/wiki/Honeypot_(computing)#Spam_versions)
without polluting the statistical module.
Rspamd uses the conjunction of different techniques to make the finall decision about a message. This allows to improve the overall quality of filtering and reduce the number of
false positives (e.g. when a innocent message is badly classified as a spam one). I have tried to simplify rspamd usage by adding the following elements:
-* **Web interface** - rspamd is shipped with the fully functional ajax based web interface that allows to observe rspamd statistic; to configure rules, weights and lists; to scan
+* **Web interface** - rspamd is shipped with the fully functional ajax-based web interface that allows to observe rspamd statistic, to configure rules, weights and lists, to scan
and learn messages and to view the history of scans. The interface is self-hosted, requires zero configuration and follows the recent web applications standards. You don't need a
web server or applications server to run web UI - you just need to run rspamd itself and a web browser.
* **Dynamic tables** - rspamd allows to specify some data as `dynamic maps` that are checked in runtime with updating data when they are changed. Rspamd supports file and HTTP maps.
-## Performancу
+## Performance
-Rspamd is designed to be fast. The core of rspamd is written in `C` and uses event-driven model that allows to process multiple messages simultaenously and without blocking.
-Moreover, a set of techniques was used in rspamd to process messages faster:
+Rspamd is designed to be fast. The core of rspamd is written in `C` and uses an event-driven model that allows to process multiple messages simultaneously and without blocking.
+Moreover, a set of techniques is used in rspamd to process messages faster:
* **Finite state machines processing** - rspamd uses specialized finite state machines for the performance critical tasks to process input faster than a set of regular expressions.
Of course, it is possible to implement these machines by ordinary `perl regular expressions` but then they won't be compact or human-readable. On the contrary, rspamd optimizes
-such actions as headers processing, received elements extraction, protocol operations by builiding the conrete automata for an assigned task.
+such actions as headers processing, received elements extraction, protocol operations by building the concrete automata for an assigned task.
-* **Expressions optimizer** - allows to optimize expressions by exectution of `likely false` or `likely true` expressions in order in the branches. That allows to reduce number of
+* **Expressions optimizer** - allows to optimize expressions by execution of `likely false` or `likely true` expressions in order in the branches. That allows to reduce number of
expensive expressions calls when scanning a message.
-* **Symbols optimizer** - rspamd tries to check first the rules that are frequent or inexpensive in terms of time or CPU resourses, which allows to block spam before processing of
+* **Symbols optimizer** - rspamd tries to check first the rules that are frequent or inexpensive in terms of time or CPU resources which allows to block spam before processing of
expensive rules (rules with negative weights are always checked before other ones).
-* **Event driven model** - rspamd is designed not to block anywhere in the code and counting that spam checks requires a lot of network operations, rspamd can process many messages
+* **Event driven model** - rspamd is designed not to block anywhere in the code and knowing that a spam check requires a lot of network operations, rspamd can process many messages
simultaneously increasing the efficiency of shared DNS caches and other system resources. Moreover, event-driven system normally scales automatically and you won't need to do any
tuning in the most of cases.
-* **Threaded expressions and statistics** - rspamd allows to perform computation resources greedy tasks, such as regular expressions or statistics, in separate threads pools, which
-allows to scale even more on the modern multi-core systems.
+* **Threaded expressions and statistics** - rspamd allows to perform computation for resources intensive tasks -- such as regular expressions or statistics -- in separate threads pools which
+allows to scale even more on modern multi-core systems.
-* **Clever choice of data structures** - rspamd tries to use the optimal data structure for each task, for example, it uses very efficient suffix tries for fast matching of a text
+* **Clever choice of data structures** - rspamd tries to use the optimal data structure for each task. For example it uses very efficient suffix tries for fast matching of a text
against a set of multiple patterns. Or it uses radix bit trie for storing IP addresses information that provides O(1) access time complexity.
## Extensions
-Besides of the `C` core rspamd provides the extensive [LUA](http://lua.org) API to access almost all the features available directly from `C`. LUA is an extremely easy
-to learn programming language, though it is powerful enough to implement complex mail filters. In fact, rspamd has a significant amout of code written completely in lua, such as
-DNS blacklists checks, or user's settings, or different maps implementation. You can also write your own filters and rules in LUA adopting rspamd functionality to your needs.
-Furthermore, LUA programs are very fast and their performance is rather [close](http://attractivechaos.github.io/plb/) to pure `C`. However, you should mention that for the most
-of performance critical tasks you usually use the rspamd core functionality than LUA code. Anyway, you can also use `LuaJIT` with rspamd if your goal is maximum performance.
-From the LUA API you can do the following tasks:
+Besides its `C` core, rspamd provides an extensive [Lua](http://lua.org) API to access almost all the features available directly from `C`. Lua is an extremely easy
+to learn programming language though it is powerful enough to implement complex mail filters. In fact rspamd has a significant amount of code written completely in Lua such as
+DNS blacklists checks, user's settings or different maps implementation. You can also write your own filters and rules in Lua adopting rspamd functionality to your needs.
+Furthermore, Lua programs are very fast and their performance is rather [close](http://attractivechaos.github.io/plb/) to pure `C`. However, you should mention that for the most
+of performance critical tasks you usually use the rspamd core functionality than Lua code. Anyway, you can also use `LuaJIT` with rspamd if your goal is maximum performance.
+From the Lua API you can do the following tasks:
-* **Reading the configuration parameters** - lua code has the full access to the parsed configuration knobs and you can easily modify your plugins behaviour by means of the main
+* **Reading the configuration parameters** - Lua code has the full access to the parsed configuration knobs and you can easily modify your plugins behaviour by means of the main
rspamd configuration
* **Registering custom filters** - it is more than simple to add your own filters to rspamd: just add new index to the global variable `rspamd_config`:
* **Pre- and post- filters** - you can register callbacks that are called before or after messages processing to make results more precise or to make some early decision,
-for example, to implement a rate limit.
+for example to implement a rate limit.
-* **Registering functions for rspamd** - you can write your own functions in lua to extend rspamd internal expression functions.
+* **Registering functions for rspamd** - you can write your own functions in Lua to extend rspamd internal expression functions.
-* **Managing statistics** - lua scripts can define a set of statistical files to be scanned or learned for a specific message allowing to create more complex
-statistical systems, e.g. based on an input language. Moreover, you can even learn rspamd statistic from lua scripts.
+* **Managing statistics** - Lua scripts can define a set of statistical files to be scanned or learned for a specific message allowing to create more complex
+statistical systems, e.g. based on an input language. Moreover, you can even learn rspamd statistic from Lua scripts.
-* **Standalone lua applications** - you can even write your own worker based on rspamd core and performing some asynchronous logic in lua. Of course, you can use the
+* **Standalone Lua applications** - you can even write your own worker based on rspamd core and performing some asynchronous logic in Lua. Of course, you can use the
all features from rspamd core, including such features as non-blocking IO, HTTP client and server, non-blocking redis client, asynchronous DNS, UCL configuration and so on
and so forth.
-* **API documentation** - rspamd lua API has an [extensive documentation](https://rspamd.com/doc/lua) where you can find examples, references and the guide about how to extend
-rspamd with LUA.
+* **API documentation** - rspamd Lua API has an [extensive documentation](https://rspamd.com/doc/lua) where you can find examples, references and the guide about how to extend
+rspamd with Lua.
## References
projects / rspamd.git / commitdiff