class Google::Cloud::Env::FileSystem


Ruby process.
large file, its contents will stay in memory for the lifetime of the
This class does not provide any controls for data size. If you read a
is, overrides are “all or nothing”.
If overrides are present, actual file system access is disabled; that
You can also “mock” the file system by providing a hash of overrides.
the file system.
system, caching data so that subsequent accesses do not need to reread
This is a simple class that reads the contents of objects in the file
Access to file system contents.
#

def initialize


Create a file system access object with no overrides.
# 
def initialize
  @overrides = nil
  @cache = LazyDict.new do |path, binary|
    if binary
      File.binread path
    else
      File.read path
    end
  rescue IOError, SystemCallError
    nil
  end
  # This mutex protects the overrides variable. Its setting (i.e.
  # whether nil or an overrides hash) will not change within a
  # synchronize block.
  @mutex = Thread::Mutex.new
end

def overrides= new_overrides

Parameters:
  • new_overrides (Hash{String => String}, nil) -- 
def overrides= new_overrides
  @mutex.synchronize do
    @overrides = new_overrides
  end
end

def read path, binary: false

Returns:
  • (nil) - if the file does not exist.
  • (String) - if the file exists.

Parameters:
  • binary (boolean) -- Whether to read in binary mode. Defaults to
  • path (String) -- The path to the file. 
def read path, binary: false
  result = false
  @mutex.synchronize do
    result = @overrides[path] if @overrides
  end
  result = @cache.get(path, binary) if result == false
  if result && binary != (result.encoding == Encoding::ASCII_8BIT)
    raise IOError, "binary encoding flag mismatch"
  end
  result
end

def with_overrides temp_overrides

Parameters:
  • temp_overrides (nil, Hash{String => String}) -- 
def with_overrides temp_overrides
  old_overrides = @overrides
  begin
    @mutex.synchronize do
      @overrides = temp_overrides
    end
    yield
  ensure
    @mutex.synchronize do
      @overrides = old_overrides
    end
  end
end