Provide ability to see current state of DB encryption [CORE6048]

[firebird-automations]

Submitted by: @pavel-zotov

It will be good to obtain current state of encryption / decryption process or its result (finished / not started), either via RDB$GET_CONTEXT() or using new field in MON$DATABASE table.
Returned data must contain "kind" of process that currently is going (i.e. ENCryption or DECryption) and percent of its progress.
Perhaps, one can use positive number for encryption, negative for decryption and zero when there is no activity related to this.

Commits: ee4c8f2 76088c2

====== Test Details ======

Test checks presense on mon$database.mon$crypt_state column and its changing when DB is encrypted / decrypted.
Changes of mon$crypt_page column are not watched because this requires large DB and relatively slow CPU to be seen.

[firebird-automations]

Modified by: @AlexPeshkoff

assignee: Alexander Peshkov [ alexpeshkoff ]

[firebird-automations]

Commented by: @AlexPeshkoff

Added mon$crypt_state field with values as documented in README.monitoring_tables. Field mon$crypt_page, returning currently processed page (0 when no encryption/decryption in progress) is present since 3.0. Using it and MON$PAGES field percent calculation is trivial.

[firebird-automations]

Modified by: @AlexPeshkoff

status: Open [ 1 ] => Resolved [ 5 ]

resolution: Fixed [ 1 ]

Fix Version: 4.0 Beta 2 [ 10888 ]

[firebird-automations]

Modified by: @pavel-zotov

status: Resolved [ 5 ] => Resolved [ 5 ]

QA Status: No test => Done successfully

Test Details: Test checks presense on mon$database.mon$crypt_state column and its changing when DB is encrypted / decrypted.
Changes of mon$crypt_page column are not watched because this requires large DB and relatively slow CPU to be seen.

[firebird-automations]

Modified by: @pavel-zotov

status: Resolved [ 5 ] => Closed [ 6 ]