Add list-dependencies-from-patches.awk

2023-11-23 :

- Added tools/list-dependencies-from-patches.awk to list dependencies on

  POSIX systems without Bash. Provided by Jan Pobříslo (ccx)

2017-08-07 :

- Added functions to assert that user (loading patch) is either superuser, or

  is not superuser, or is one of listed users.

# USAGE

In your files with patches to database, put whole logic in single

transaction, and use \_v.\* functions - usually \_v.register_patch() at

transaction, and use \_v.\* functions - usually \_v.register\_patch() at

least to make sure everything is OK.

For example. Let's assume you have patch files:

# AVAILABLE FUNCTIONS

## \_v.register_patch( TEXT, TEXT[], TEXT[] )

## \_v.register\_patch( TEXT, TEXT[], TEXT[] )

Registers named patch (first argument), checking if all required patches (2nd

argument) are installed, and that no conflicting patches (3rd argument) are

2nd and 3rd arguments default to NULL/empty array.

## \_v.try_register_patch( TEXT, TEXT[], TEXT[] )

## \_v.try\_register\_patch( TEXT, TEXT[], TEXT[] )

Works just like \_v.register_patch(), but instead of raising exception it

Works just like \_v.register\_patch(), but instead of raising exception it

returns true if it worked, and false if it didn't.

## \_v.unregister_patch( TEXT )

## \_v.unregister\_patch( TEXT )

Removes information about given patch from the versioning data.

It doesn't remove objects that were created by this patch - just removes

metainformation.

## \_v.assert_user_is_superuser()

## \_v.assert\_user\_is\_superuser()

Make sure that current patch is being loaded by superuser.

If it's not - it will raise exception, and break transaction.

## \_v.assert_user_is_not_superuser()

## \_v.assert\_user\_is\_not\_superuser()

Make sure that current patch is not being loaded by superuser.

If it is - it will raise exception, and break transaction.

## \_v.assert_user_is_one_of(TEXT, TEXT, ... )

## \_v.assert\_user\_is\_one\_of(TEXT, TEXT, ... )

Make sure that current patch is being loaded by one of listed users.

If ```current_user``` is not listed as one of arguments - function will raise

exception and break the transaction.

# ADDITIONAL TOOLS

## list-dependencies-from-patches.sh

Helper script that scans given filenames for versioning function calls, and

extracts dependency tree in a way that allows for sorting it using

[tsort](https://www.man7.org/linux/man-pages/man1/tsort.1.html).

## list-dependencies-from-patches.awk

Implementation of the dependency listing tool, in awk, without depending on

Bash. Provided by Jan Pobříslo (ccx).

# SUPPORT

If you'd like to suggest new functionality or ask anything - please use

#!/bin/awk -f

# Simple tool to list dependencies in form suitable for tsort utility.

# Run this script like this:

#   /some/path/list-dependencies-from-patches.awk *.sql | tsort | tac

# To get patches in order that satisfies dependencies while loading them.

tolower($0) ~ /^[[:space:]]*select[[:space:]]+_v.register_patch\(/ {

    if(!match($0, /\([[:space:]]*'/)) {

        print "warning: malformed register_patch line: "FILENAME":"FNR >"/dev/stderr"

        print "no patch name found" >"/dev/stderr"

        next

    }

    line_remaining = substr($0, RSTART + RLENGTH)

    if(!match(line_remaining, /'/)) {

        print "warning: malformed register_patch line: "FILENAME":"FNR >"/dev/stderr"

        print "not end of patch name" >"/dev/stderr"

        next

    }

    patch_name = substr(line_remaining, 1, RSTART - 1)

    line_remaining = substr(line_remaining, RSTART + RLENGTH)

    print patch_name " " patch_name;

    if(!match(line_remaining, /[[:space:]]*,[[:space:]]*ARRAY\[[[:space:]]*'/)) {

        next

    }

    line_remaining = substr(line_remaining, RSTART + RLENGTH)

    while(match(line_remaining, /[[:space:]]*,[[:space:]]*ARRAY\[[[:space:]]*'/)) {

        print patch_name " " substr(line_remaining, 1, RSTART - 1)

        line_remaining = substr(line_remaining, RSTART + RLENGTH)

    }

    if(!match(line_remaining, /'/)) {

        print "warning: malformed register_patch line: "FILENAME":"FNR >"/dev/stderr"

        print "not end of dependency name" >"/dev/stderr"

        next

    }

    print patch_name " " substr(line_remaining, 1, RSTART - 1)

}