Class: PackfileReader::Hunk

Inherits:
Object
  • Object
show all
Defined in:
lib/packfile_reader/packfile_hunk.rb

Constant Summary collapse

TYPE_MAP = 
{
  1 => :OBJ_COMMIT,
  2 => :OBJ_TREE,
  3 => :OBJ_BLOB,
  4 => :OBJ_TAG,
  6 => :OBJ_OFS_DELTA,
  7 => :OBJ_REF_DELTA,
}
HUNK_TYPE_MASK = 
0b01110000
HUNK_SIZE_4_MASK = 
0b00001111
HUNK_SIZE_7_MASK = 
0b01111111

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#offset_size ⇒ Object (readonly)

Returns the value of attribute offset_size.



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# File 'lib/packfile_reader/packfile_hunk.rb', line 5

def offset_size
  @offset_size
end

#size ⇒ Object (readonly)

Returns the value of attribute size.



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# File 'lib/packfile_reader/packfile_hunk.rb', line 3

def size
  @size
end

#type ⇒ Object (readonly)

Returns the value of attribute type.



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# File 'lib/packfile_reader/packfile_hunk.rb', line 4

def type
  @type
end

Class Method Details

.new_with_type(packfile_io) ⇒ Object 



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# File 'lib/packfile_reader/packfile_hunk.rb', line 20

def self.new_with_type(packfile_io)
  hunk_bytes = packfile_io.read(1).unpack('C')[0]
  continuation = hunk_bytes[7] # First representative bit of the byte
  type = (hunk_bytes & HUNK_TYPE_MASK) >> 4 # Adjust type position (remove the extra 4 bits at the end)
  size = (hunk_bytes & HUNK_SIZE_4_MASK) # We only have 4 bits in a hunk with type for size

  Hunk.new(continuation == 1, size, 4, TYPE_MAP[type])
end

.new_without_type(packfile_io) ⇒ Object 



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# File 'lib/packfile_reader/packfile_hunk.rb', line 29

def self.new_without_type(packfile_io)
  hunk_bytes = packfile_io.read(1).unpack('C')[0]
  continuation = hunk_bytes[7] # First representative bit of the byte
  size = (hunk_bytes & HUNK_SIZE_7_MASK) # We only have 7 bits in a hunk with type for size

  Hunk.new(continuation == 1, size, 7)
end

Instance Method Details

#continuation? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/packfile_reader/packfile_hunk.rb', line 37

def continuation?
  @continuation
end