Fixes indices. Checks them before adding new elements.

This commit is contained in:
Luka Vandervelden 2019-12-10 21:26:15 +01:00
parent 7079e5ae91
commit 1fb7446e4a
2 changed files with 76 additions and 5 deletions

View File

@ -104,9 +104,13 @@ class FS::Hash(K, V)
end end
def []=(key : K, value : V) def []=(key : K, value : V)
old_value = self.[key]?
check_collisions! key, value, old_value
# Removes any old indices or partitions pointing to a value about # Removes any old indices or partitions pointing to a value about
# to be replaced. # to be replaced.
self.[key]?.try do |old_value| if old_value
remove_partitions key, old_value remove_partitions key, old_value
end end
@ -119,16 +123,36 @@ class FS::Hash(K, V)
write_partitions key, value write_partitions key, value
end end
def check_collisions!(key : K, value : V, old_value : V?)
@partitions.each do |index|
case index
when IndexData
index_key = index.key_proc.call value
symlink = file_path_indexes(index_key.to_s, index.name)
# FIXME: Check its not pointing to “old_value”, if any.
pp! symlink
if ::File.exists? symlink
raise IndexOverload.new "Index '#{index.name}' is overloaded for key '#{key}'"
end
end
end
end
def write_partitions(key : K, value : V) def write_partitions(key : K, value : V)
@partitions.each do |index| @partitions.each do |index|
index_key = index.key_proc.call value index_key = index.key_proc.call value
case index case index
when IndexData when IndexData
symlink = file_path_indexes(key.to_s, index.name) symlink = file_path_indexes(index_key, index.name)
Dir.mkdir_p ::File.dirname symlink Dir.mkdir_p ::File.dirname symlink
# FIXME: A check_collisions! is done a bit higher. Is this
# still required?
if ::File.exists? symlink if ::File.exists? symlink
raise Exception.new "symlink already exists: #{symlink}" raise Exception.new "symlink already exists: #{symlink}"
end end
@ -183,7 +207,7 @@ class FS::Hash(K, V)
case index case index
when IndexData when IndexData
symlink = file_path_indexes(key.to_s, index.name) symlink = file_path_indexes(index_key, index.name)
::File.delete symlink ::File.delete symlink
when PartitionData when PartitionData
@ -260,8 +284,8 @@ class FS::Hash(K, V)
"#{@directory_name}/tags/by_#{name}" "#{@directory_name}/tags/by_#{name}"
end end
private def file_path_indexes(key : String, index_name : String) private def file_path_indexes(index_key : String, index_name : String)
"#{dir_path_indexes index_name}/#{key}.json" "#{dir_path_indexes index_name}/#{index_key}.json"
end end
private def file_path_partition(key : String, index_name : String, index_key : String) private def file_path_partition(key : String, index_name : String, index_key : String)
@ -289,3 +313,6 @@ class FS::Hash(K, V)
end end
end end
class FS::IndexOverload < Exception
end

44
test-index.cr Normal file
View File

@ -0,0 +1,44 @@
require "json"
require "./src/fs.cr"
require "uuid"
# This test basically works if no data is obtained when fetching "broken"
# partitions/indices/tags.
class Ship
JSON.mapping({
id: String,
class: String,
name: String,
tags: Array(String)
})
def initialize(@name, @class = @name, @tags = [] of String)
@id = UUID.random.to_s
end
getter name
getter id
end
ships = FS::Hash(String, Ship).new "test-index"
by_name = ships.new_index "name", &.name
by_class = ships.new_partition "class", &.class
by_id = ships.new_index "id", &.id
by_tags = ships.new_tags "tags", &.tags
ship = Ship.new "Mutsuki", "Mutsuki", tags: ["kuchikukan"]
ships[ship.id] = ship
begin
ship = Ship.new "Mutsuki", "broken", tags: ["kuchikukan"]
ships[ship.id] = ship
rescue FS::IndexOverload
puts "rescue: Adding an entry that would overload an index has been prevented."
# Should happen, ignore it.
else
puts "ERROR: No IndexOverload exception was raised on index overload."
end
pp! ships.get_index("name").map &.name