def write_signed_vint(self, i):
"""
Helper method for writing 32-bit signed value, using
"zig zag encoding" (see protocol buffers for explanation -- basically,
sign bit is moved as LSB, rest of value shifted left by one)
coupled with basic variable length encoding
:param int i: Signed int
"""
self.write_positive_vint(util.zigzag_encode(i))
def write_signed_vint(self, i):
"""
Helper method for writing 32-bit signed value, using
"zig zag encoding" (see protocol buffers for explanation -- basically,
sign bit is moved as LSB, rest of value shifted left by one)
coupled with basic variable length encoding
:param int i: Signed int
"""
self.write_positive_vint(util.zigzag_encode(i))
def write_number(self, i):
"""
Write Numner
:param int|long|float|str i: number
"""
if isinstance(i, int):
# First things first: let's zigzag encode number
i = util.zigzag_encode(i)
# tiny (single byte) or small (type + 6-bit value) number?
if 0x3F >= i >= 0:
if i <= 0x1F:
self.write_byte(int((TOKEN_PREFIX_SMALL_INT + i)))
return
# nope, just small, 2 bytes (type, 1-byte zigzag value) for 6 bit value
self.write_bytes(TOKEN_BYTE_INT_32, int((0x80 + i)))
return
# Ok: let's find minimal representation then
b0 = int((0x80 + (i & 0x3F)))
i >>= 6
if i <= 0x7F:
# 13 bits is enough (== 3 byte total encoding)
self.write_bytes(TOKEN_BYTE_INT_32, int(i), b0)
return
b1 = int((i & 0x7F))
i >>= 7
if i <= 0x7F:
self.write_bytes(TOKEN_BYTE_INT_32, int(i), b1, b0)
return
b2 = int((i & 0x7F))
i >>= 7
if i <= 0x7F:
self.write_bytes(TOKEN_BYTE_INT_32, int(i), b2, b1, b0)
return
# no, need all 5 bytes
b3 = int((i & 0x7F))
self.write_bytes(TOKEN_BYTE_INT_32, int((i >> 7)), b3, b2, b1, b0)
elif isinstance(i, long):
# First: maybe 32 bits is enough?
if MAX_INT_AS_LONG >= i >= MIN_INT_AS_LONG:
return self.write_number(int(i))
# Then let's zigzag encode it
l = util.zigzag_encode(i)
# Ok, well, we do know that 5 lowest-significant bytes are needed
i = int(l)
# 4 can be extracted from lower int
b0 = int((0x80 + (i & 0x3F)))
# sign bit set in the last byte
b1 = int(((i >> 6) & 0x7F))
b2 = int(((i >> 13) & 0x7F))
b3 = int(((i >> 20) & 0x7F))
# fifth one is split between ints:
l = bsr(l, 27)
b4 = int(((int(l)) & 0x7F))
# which may be enough?
i = int((l >> 7))
if i == 0:
self.write_bytes(TOKEN_BYTE_INT_64, b4, b3, b2, b1, b0)
return
if i <= 0x7F:
self.write_bytes(TOKEN_BYTE_INT_64, int(i), b4, b3, b2, b1, b0)
return
b5 = int((i & 0x7F))
i >>= 7
if i <= 0x7F:
self.write_bytes(TOKEN_BYTE_INT_64, int(i), b5, b4, b3, b2, b1, b0)
return
b6 = int((i & 0x7F))
i >>= 7
if i <= 0x7F:
self.write_bytes(TOKEN_BYTE_INT_64, int(i), b6, b5, b4, b3, b2, b1, b0)
return
b7 = int((i & 0x7F))
i >>= 7
if i <= 0x7F:
self.write_bytes(TOKEN_BYTE_INT_64, int(i), b7, b6, b5, b4, b3, b2, b1, b0)
return
b8 = int((i & 0x7F))
i >>= 7
# must be done, with 10 bytes! (9 * 7 + 6 == 69 bits; only need 63)
self.write_bytes(TOKEN_BYTE_INT_64, int(i), b8, b7, b6, b5, b4, b3, b2, b1, b0)
elif isinstance(i, basestring):
if not i:
self.write_null()
return
neg = i.startswith('-')
i = i.strip('-')
if i.isdigit():
self.write_integral_number(i, neg)
else:
self.write_decimal_number(i)
elif isinstance(i, (float, decimal.Decimal)):
if isinstance(i, decimal.Decimal) and isinstance(int(float(i)), long):
self.write_byte(TOKEN_BYTE_BIG_DECIMAL)
scale = i.as_tuple().exponent
self.write_signed_vint(scale)
self.write_7bit_binary(bytearray(str(i.to_integral_value())))
else:
i = float(i)
try:
i = util.float_to_bits(i)
self.write_byte(TOKEN_BYTE_FLOAT_32)
self.write_byte(int(i & 0x7F))
for _ in xrange(4):
i >>= 7
self.write_byte(int(i & 0x7F))
except struct.error:
i = util.float_to_raw_long_bits(i)
self.write_byte(TOKEN_BYTE_FLOAT_64)
self.write_byte(int(i & 0x7F))
for _ in xrange(9):
i >>= 7
self.write_byte(int(i & 0x7F))
def write_number(self, i):
"""
Write Numner
:param int|long|float|str i: number
"""
if isinstance(i, int):
# First things first: let's zigzag encode number
i = util.zigzag_encode(i)
# tiny (single byte) or small (type + 6-bit value) number?
if 0x3F >= i >= 0:
if i <= 0x1F:
self.write_byte(int((TOKEN_PREFIX_SMALL_INT + i)))
return
# nope, just small, 2 bytes (type, 1-byte zigzag value) for 6 bit value
self.write_bytes(TOKEN_BYTE_INT_32, int((0x80 + i)))
return
# Ok: let's find minimal representation then
b0 = int((0x80 + (i & 0x3F)))
i >>= 6
if i <= 0x7F:
# 13 bits is enough (== 3 byte total encoding)
self.write_bytes(TOKEN_BYTE_INT_32, int(i), b0)
return
b1 = int((i & 0x7F))
i >>= 7
if i <= 0x7F:
self.write_bytes(TOKEN_BYTE_INT_32, int(i), b1, b0)
return
b2 = int((i & 0x7F))
i >>= 7
if i <= 0x7F:
self.write_bytes(TOKEN_BYTE_INT_32, int(i), b2, b1, b0)
return
# no, need all 5 bytes
b3 = int((i & 0x7F))
self.write_bytes(TOKEN_BYTE_INT_32, int((i >> 7)), b3, b2, b1, b0)
elif isinstance(i, long):
# First: maybe 32 bits is enough?
if MAX_INT_AS_LONG >= i >= MIN_INT_AS_LONG:
return self.write_number(int(i))
# Then let's zigzag encode it
l = util.zigzag_encode(i)
# Ok, well, we do know that 5 lowest-significant bytes are needed
i = int(l)
# 4 can be extracted from lower int
b0 = int((0x80 + (i & 0x3F)))
# sign bit set in the last byte
b1 = int(((i >> 6) & 0x7F))
b2 = int(((i >> 13) & 0x7F))
b3 = int(((i >> 20) & 0x7F))
# fifth one is split between ints:
l = bsr(l, 27)
b4 = int(((int(l)) & 0x7F))
# which may be enough?
i = int((l >> 7))
if i == 0:
self.write_bytes(TOKEN_BYTE_INT_64, b4, b3, b2, b1, b0)
return
if i <= 0x7F:
self.write_bytes(TOKEN_BYTE_INT_64, int(i), b4, b3, b2, b1, b0)
return
b5 = int((i & 0x7F))
i >>= 7
if i <= 0x7F:
self.write_bytes(TOKEN_BYTE_INT_64, int(i), b5, b4, b3, b2, b1,
b0)
return
b6 = int((i & 0x7F))
i >>= 7
if i <= 0x7F:
self.write_bytes(TOKEN_BYTE_INT_64, int(i), b6, b5, b4, b3, b2,
b1, b0)
return
b7 = int((i & 0x7F))
i >>= 7
if i <= 0x7F:
self.write_bytes(TOKEN_BYTE_INT_64, int(i), b7, b6, b5, b4, b3,
b2, b1, b0)
return
b8 = int((i & 0x7F))
i >>= 7
# must be done, with 10 bytes! (9 * 7 + 6 == 69 bits; only need 63)
self.write_bytes(TOKEN_BYTE_INT_64, int(i), b8, b7, b6, b5, b4, b3,
b2, b1, b0)
elif isinstance(i, basestring):
if not i:
self.write_null()
return
neg = i.startswith('-')
i = i.strip('-')
if i.isdigit():
self.write_integral_number(i, neg)
else:
self.write_decimal_number(i)
elif isinstance(i, (float, decimal.Decimal)):
if isinstance(i, decimal.Decimal) and isinstance(
int(float(i)), long):
self.write_byte(TOKEN_BYTE_BIG_DECIMAL)
scale = i.as_tuple().exponent
self.write_signed_vint(scale)
self.write_7bit_binary(bytearray(str(i.to_integral_value())))
else:
i = float(i)
try:
i = util.float_to_bits(i)
self.write_byte(TOKEN_BYTE_FLOAT_32)
self.write_byte(int(i & 0x7F))
for _ in xrange(4):
i >>= 7
self.write_byte(int(i & 0x7F))
except struct.error:
i = util.float_to_raw_long_bits(i)
self.write_byte(TOKEN_BYTE_FLOAT_64)
self.write_byte(int(i & 0x7F))
for _ in xrange(9):
i >>= 7
self.write_byte(int(i & 0x7F))