Virtual hosts for data collection (#14464)

* support multiple hosts at pluginsd structures

* cleanup obsolete code

* use a lookup hashtable to quickly find the keyword to execute, without traversing the whole linked list of keywords

* more cleanup

* move new hash function to inlined.h

* minimize comparisons, eliminate a pre-parsing of the first keyword for each line

* cleanup parser from old code

* move parser into libnetdata

* unique entries in parser keywords hashtable

* move all hashing functions to inlined.h, name their sources, simple_hash() now defaults to FNV1a, it was FNV1

* small_hash() for parser

* plugins.d now can switch hosts, and also create/update them

* update hash function and hashtable size

* updated message

* unittest all hashing functions

* reset the chart when setting a new host

* remove host tags

* enable archived hosts when a collector pushes host info

* do not need localhost to swtich to localhost

* disable ARAL and OWA with -DFSANITIZE_ADDRESS=1

1 files changed, 0 insertions, 156 deletions

diff --git a/parser/README.md b/parser/README.md
deleted file mode 100644
index cf59bfd767..0000000000
--- a/parser/README.md
+++ /dev/null
@@ -1,156 +0,0 @@
-<!--
-title: "Parser"
-custom_edit_url: https://github.com/netdata/netdata/blob/master/parser/README.md
-sidebar_label: "Parser"
-learn_status: "Published"
-learn_topic_type: "References"
-learn_rel_path: "Developers/Database"
--->
-
-
-#### Introduction
-
-The parser will be used to process streaming and plugins input as well as metadata
-
-Usage
-
-1. Define a structure that will be used to share user state across calls 
-1. Initialize the parser using `parser_init`
-2. Register keywords and associated callback function using `parser_add_keyword`
-3. Register actions on the keywords 
-4. Start a loop until EOF
-   1.  Fetch the next line using `parser_next`
-   2.  Process the line using `parser_action` 
-       1. The registered callbacks are executed to parse the input
-       2. The registered action for the callback is called for processing
-4. Release the parser using `parser_destroy`
-5. Release the user structure
-
-#### Functions
-
-TODO:
-
-##### parse_init(RRDHOST *host, void *user, void *input, int flags)
-
-Initialize an internal parser with the specified user defined data structure that will be shared across calls.
-
-Input
-- Host
-  - The host this parser will be dealing with. For streaming with SSL enabled for this host
-- user
-  - User defined structure that is passed in all the calls
-- input
-  - Where the parser will get the input from
-- flags
-  - flags to define processing on the input
-
-Output
-- A parser structure
-  
-
-
-##### parse_push(PARSER *parser, char *line)
-
-Push a new line for processing
-
-Input
-
-- parser
-  - The parser object as returned by the `parser_init`
-- line
-  - The new line to process
-    
-
-Output
-- The line will be injected into the stream and will be the next one to be processed
-  
-Returns
-- 0 line added
-- 1 error detected
-  
-
-##### parse_add_keyword(PARSER *parser, char *keyword, keyword_function callback_function)
-
-The function will add callbacks for keywords. The callback function is defined as
-
-`typedef PARSER_RC (*keyword_function)(char **, void *);`
-
-Input
-
-- parser
-  - The parser object as returned by the `parser_init`
-- keyword
-  - The keyword to register
-- keyword_function
-  - The callback that will handle the keyword processing
-    * The callback function should return one of the following
-      * PARSER_RC_OK - Callback was successful (continue with other callbacks)
-      * PARSER_RC_STOP - Stop processing callbacks (return OK)
-      * PARSER_RC_ERROR - Callback failed, exit
-
-Output
-- The corresponding keyword and callback will be registered
-  
-Returns
-- 0 maximum callbacks already registered for this keyword
-- > 0 which is the number of callbacks associated with this keyword.
-
-   
-##### parser_next(PARSER *parser)
-Return the next item to parse
-
-Input
-- parser
-  - The parser object as returned by the `parser_init`
-  
-Output
-- The parser will store internally the next item to parse
-
-Returns
-- 0 Next item fetched successfully
-- 1 No more items to parse
-
-
-##### parser_action(PARSER *parser, char *input)
-Return the next item to parse
-
-Input
-- parser
-  - The parser object as returned by the `parser_init`
-- input
-  - Process the input specified instead of using the internal buffer
-  
-Output
-- The current keyword will be processed by calling all the registered callbacks
-
-Returns
-- 0 Callbacks called successfully
-- 1 Failed
-
-
-##### parser_destroy(PARSER *parser)
-Cleanup a previously allocated parser
-
-Input
-- parser
-  - The parser object as returned by the `parser_init`
-  
-Output
-- The parser is deallocated
-
-Returns
-- none
-  
-
-##### parser_recover_input(PARSER *parser)
-Cleanup a previously allocated parser
-
-Input
-- parser
-  - The parser object as returned by the `parser_init`
-  
-Output
-- The parser is deallocated
-
-Returns
-- none