debian-mirror-gitlab/lib/gitlab/ci/trace/chunked_io.rb
2019-01-03 12:48:30 +05:30

242 lines
5.7 KiB
Ruby

# frozen_string_literal: true
##
# This class is compatible with IO class (https://ruby-doc.org/core-2.3.1/IO.html)
# source: https://gitlab.com/snippets/1685610
module Gitlab
module Ci
class Trace
class ChunkedIO
CHUNK_SIZE = ::Ci::BuildTraceChunk::CHUNK_SIZE
FailedToGetChunkError = Class.new(StandardError)
attr_reader :build
attr_reader :tell, :size
attr_reader :chunk, :chunk_range
alias_method :pos, :tell
def initialize(build, &block)
@build = build
@chunks_cache = []
@tell = 0
@size = calculate_size
yield self if block_given?
end
def close
# no-op
end
def binmode
# no-op
end
def binmode?
true
end
def seek(pos, where = IO::SEEK_SET)
new_pos =
case where
when IO::SEEK_END
size + pos
when IO::SEEK_SET
pos
when IO::SEEK_CUR
tell + pos
else
-1
end
raise ArgumentError, 'new position is outside of file' if new_pos < 0 || new_pos > size
@tell = new_pos
end
def eof?
tell == size
end
def each_line
until eof?
line = readline
break if line.nil?
yield(line)
end
end
def read(length = nil, outbuf = nil)
out = []
length ||= size - tell
until length <= 0 || eof?
data = chunk_slice_from_offset
break if data.empty?
chunk_bytes = [CHUNK_SIZE - chunk_offset, length].min
chunk_data = data.byteslice(0, chunk_bytes)
out << chunk_data
@tell += chunk_data.bytesize
length -= chunk_data.bytesize
end
out = out.join
# If outbuf is passed, we put the output into the buffer. This supports IO.copy_stream functionality
if outbuf
outbuf.replace(out)
end
out
end
def readline
out = []
until eof?
data = chunk_slice_from_offset
new_line = data.index("\n")
if !new_line.nil?
out << data[0..new_line]
@tell += new_line + 1
break
else
out << data
@tell += data.bytesize
end
end
out.join
end
def write(data)
start_pos = tell
while tell < start_pos + data.bytesize
# get slice from current offset till the end where it falls into chunk
chunk_bytes = CHUNK_SIZE - chunk_offset
chunk_data = data.byteslice(tell - start_pos, chunk_bytes)
# append data to chunk, overwriting from that point
ensure_chunk.append(chunk_data, chunk_offset)
# move offsets within buffer
@tell += chunk_data.bytesize
@size = [size, tell].max
end
tell - start_pos
ensure
invalidate_chunk_cache
end
# rubocop: disable CodeReuse/ActiveRecord
def truncate(offset)
raise ArgumentError, 'Outside of file' if offset > size || offset < 0
return if offset == size # Skip the following process as it doesn't affect anything
@tell = offset
@size = offset
# remove all next chunks
trace_chunks.where('chunk_index > ?', chunk_index).fast_destroy_all
# truncate current chunk
current_chunk.truncate(chunk_offset)
ensure
invalidate_chunk_cache
end
# rubocop: enable CodeReuse/ActiveRecord
def flush
# no-op
end
def present?
true
end
def destroy!
trace_chunks.fast_destroy_all
@tell = @size = 0
ensure
invalidate_chunk_cache
end
private
##
# The below methods are not implemented in IO class
#
def in_range?
@chunk_range&.include?(tell)
end
def chunk_slice_from_offset
unless in_range?
current_chunk.tap do |chunk|
raise FailedToGetChunkError unless chunk
@chunk = chunk.data
@chunk_range = chunk.range
end
end
@chunk[chunk_offset..CHUNK_SIZE]
end
def chunk_offset
tell % CHUNK_SIZE
end
def chunk_index
tell / CHUNK_SIZE
end
def chunk_start
chunk_index * CHUNK_SIZE
end
def chunk_end
[chunk_start + CHUNK_SIZE, size].min
end
def invalidate_chunk_cache
@chunks_cache = []
end
# rubocop: disable CodeReuse/ActiveRecord
def current_chunk
@chunks_cache[chunk_index] ||= trace_chunks.find_by(chunk_index: chunk_index)
end
# rubocop: enable CodeReuse/ActiveRecord
def build_chunk
@chunks_cache[chunk_index] = ::Ci::BuildTraceChunk.new(build: build, chunk_index: chunk_index)
end
def ensure_chunk
current_chunk || build_chunk
end
# rubocop: disable CodeReuse/ActiveRecord
def trace_chunks
::Ci::BuildTraceChunk.where(build: build)
end
# rubocop: enable CodeReuse/ActiveRecord
# rubocop: disable CodeReuse/ActiveRecord
def calculate_size
trace_chunks.order(chunk_index: :desc).first.try(&:end_offset).to_i
end
# rubocop: enable CodeReuse/ActiveRecord
end
end
end
end