ó
SÉLjc @ sš d Z d Z d d l Z d d l Z e j r6 e Z n d d l m Z d d l m Z d d l
m Z d Z e Z
e d Z e j Z d „ Z d
„ Z e d( e ƒ Z e d e ƒ Z e d* e ƒ Z e d
e ƒ Z d „ Z d „ Z d „ Z d „ Z d „ Z d „ Z d „ Z e e j e ƒ Z e e j e ƒ Z e e j e ƒ Z! e e j e ƒ Z" e e j e e j# ƒ Z$ e e j e e j# ƒ Z% e e j& d ƒ Z' e e j( d ƒ Z) e e j& d ƒ Z* e e j( d ƒ Z+ e ƒ Z, e ƒ Z- e e j e e. ƒ Z/ d „ Z0 d „ Z1 d „ Z2 d „ Z3 e j4 d e j5 ƒ Z6 d „ Z7 d „ Z8 d „ Z9 d „ Z: d! „ Z; d" „ Z< d# „ Z= d$ „ Z> d% „ Z? d& „ Z@ e@ ƒ ZA d S(+ sÏ Code for decoding protocol buffer primitives.
This code is very similar to encoder.py -- read the docs for that module first.
A "decoder" is a function with the signature:
Decode(buffer, pos, end, message, field_dict)
The arguments are:
buffer: The string containing the encoded message.
pos: The current position in the string.
end: The position in the string where the current message ends. May be
less than len(buffer) if we're reading a sub-message.
message: The message object into which we're parsing.
field_dict: message._fields (avoids a hashtable lookup).
The decoder reads the field and stores it into field_dict, returning the new
buffer position. A decoder for a repeated field may proactively decode all of
the elements of that field, if they appear consecutively.
Note that decoders may throw any of the following:
IndexError: Indicates a truncated message.
struct.error: Unpacking of a fixed-width field failed.
message.DecodeError: Other errors.
Decoders are expected to raise an exception if they are called with pos > end.
This allows callers to be lax about bounds checking: it's fineto read past
"end" as long as you are sure that someone else will notice and throw an
exception later on.
Something up the call stack is expected to catch IndexError and struct.error
and convert them to message.DecodeError.
Decoders are constructed using decoder constructors with the signature:
MakeDecoder(field_number, is_repeated, is_packed, key, new_default)
The arguments are:
field_number: The field number of the field we want to decode.
is_repeated: Is the field a repeated field? (bool)
is_packed: Is the field a packed field? (bool)
key: The key to use when looking up the field within field_dict.
(This is actually the FieldDescriptor but nothing in this
file should depend on that.)
new_default: A function which takes a message object as a parameter and
returns a new instance of the default value for this field.
(This is called for repeated fields and sub-messages, when an
instance does not already exist.)
As with encoders, we define a decoder constructor for every type of field.
Then, for every field of every message class we construct an actual decoder.
That decoder goes into a dict indexed by tag, so when we decode a message
we repeatedly read a tag, look up the corresponding decoder, and invoke it.
s kenton@google.com (Kenton Varda)iÿÿÿÿN( t encoder( t wire_format( t messageg ði c s ‡ ‡ f d † } | S( s¢ Return an encoder for a basic varint value (does not include tag).
Decoded values will be bitwise-anded with the given mask before being
returned, e.g. to limit them to 32 bits. The returned decoder does not
take the usual "end" parameter -- the caller is expected to do bounds checking
after the fact (often the caller can defer such checking until later). The
decoder returns a (value, new_pos) pair.
c s” d } d } x t j | | ƒ } | | d @| >O} | d 7} | d @sg | ˆ M} ˆ | ƒ } | | f S| d 7} | d k r t d ƒ ‚ q q Wd S( Ni i i i€ i i@ s$ Too many bytes when decoding varint.( t sixt
indexbytest _DecodeError( t buffert post resultt shiftt b( t maskt result_type( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt DecodeVarintu s
( ( R R R
( ( R R sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt _VarintDecoderk s
c s5 d | d >‰ d | >d ‰ ‡ ‡ ‡ f d † } | S( s0 Like _VarintDecoder() but decodes signed values.i c s¢ d } d } x t j | | ƒ } | | d @| >O} | d 7} | d @su | ˆ M} | ˆ Aˆ } ˆ | ƒ } | | f S| d 7} | d k r t d ƒ ‚ q q Wd S( Ni i i i€ i i@ s$ Too many bytes when decoding varint.( R R R ( R R R R R
( R R t signbit( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyR
Πs
( ( t bitsR R
( ( R R R sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt _SignedVarintDecoder† s i i@ i c C sQ | } x$ t j | | ƒ d @r, | d 7} q W| d 7} t j | | | !ƒ | f S( sç Read a tag from the buffer, and return a (tag_bytes, new_pos) tuple.
We return the raw bytes of the tag rather than decoding them. The raw
bytes can then be used to look up the proper decoder. This effectively allows
us to trade some work that would be done in pure-python (decoding a varint)
for work that is done in C (searching for a byte string in a hash table).
In a low-level language it would be much cheaper to decode the varint and
use that, but not in Python.
i€ i ( R R t binary_type( R R t start( ( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt ReadTag© s
c s ‡ ‡ f d † } | S( sØ Return a constructor for a decoder for fields of a particular type.
Args:
wire_type: The field's wire type.
decode_value: A function which decodes an individual value, e.g.
_DecodeVarint()
c s… | r( t ‰ ‡ ‡ ‡ ‡ f d † } | S| rk t j | ˆ ƒ ‰ t ˆ ƒ ‰ ‡ ‡ ‡ ‡ ‡ f d † } | S‡ ‡ f d † } | Sd S( Nc sË | j ˆ ƒ } | d k r6 | j ˆ ˆ | ƒ ƒ } n ˆ | | ƒ \ } } | | 7} | | k rp t d ƒ ‚ n x2 | | k r¤ ˆ | | ƒ \ } } | j | ƒ qs W| | k rÇ | d =t d ƒ ‚ n | S( Ns Truncated message.iÿÿÿÿs Packed element was truncated.( t gett Nonet
setdefaultR t append( R R t endR t
field_dictt valuet endpointt element( t decode_valuet keyt local_DecodeVarintt new_default( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt DecodePackedFieldÊ s
c s« | j ˆ ƒ } | d k r6 | j ˆ ˆ | ƒ ƒ } n xn ˆ | | ƒ \ } } | j | ƒ | ˆ } | | | !ˆ k s„ | | k r9 | | k rŸ t d ƒ ‚ n | Sq9 Wd S( Ns Truncated message.( R R R R R ( R R R R R R R t new_pos( R R R! t tag_bytest tag_len( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt DecodeRepeatedFieldÝ s
c s? ˆ | | ƒ \ | ˆ <} | | k r; | ˆ =t d ƒ ‚ n | S( Ns Truncated message.( R ( R R R R R ( R R ( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt DecodeFieldî s
( t
_DecodeVarintR t TagBytest len( t field_numbert is_repeatedt is_packedR R! R" R& R' ( R t wire_type( R R R! R$ R% sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt SpecificDecoderÇ s ( ( R. R R/ ( ( R R. sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt _SimpleDecoder¾ s /c s ‡ ‡ f d † } t | | ƒ S( s† Like SimpleDecoder but additionally invokes modify_value on every value
before storing it. Usually modify_value is ZigZagDecode.
c s% ˆ | | ƒ \ } } ˆ | ƒ | f S( N( ( R R R R# ( R t modify_value( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt InnerDecode s ( R0 ( R. R R1 R2 ( ( R R1 sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt _ModifiedDecoderù s c s: t j ˆ ƒ ‰ t j ‰ ‡ ‡ ‡ f d † } t | | ƒ S( s Return a constructor for a decoder for a fixed-width field.
Args:
wire_type: The field's wire type.
format: The format string to pass to struct.unpack().
c s. | ˆ } ˆ ˆ | | | !ƒ d } | | f S( Ni ( ( R R R# R ( t formatt local_unpackt
value_size( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyR2 s
( t structt calcsizet unpackR0 ( R. R4 R2 ( ( R4 R5 R6 sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt _StructPackDecoder s c s( t j ‰ ‡ f d † } t t j | ƒ S( s‡ Returns a decoder for a float field.
This code works around a bug in struct.unpack for non-finite 32-bit
floating-point values.
c sž | d } | | | !} | d d !d k r | d d !d k r | d d !d k rZ t | f S| d d !d k rw t | f St | f Sˆ d | ƒ d } | | f S(
Ni i s ÿi s €i s €s ÿs t | | ƒ \ } } | | 7} | | k r: t d ƒ ‚ n | S( s9 Skip a length-delimited value. Returns the new position.s Truncated message.( R( R ( R R R RS ( ( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt _SkipLengthDelimited s
c C sK xD t | | ƒ \ } } t | | | | ƒ } | d k r= | S| } q Wd S( s* Skip sub-group. Returns the new position.iÿÿÿÿN( R R` ( R R R R$ R# ( ( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt
_SkipGroup s c C s d S( sF Skipping an END_GROUP tag returns -1 to tell the parent loop to break.iÿÿÿÿ( ( R R R ( ( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt _EndGroup$ s c C s) | d 7} | | k r% t d ƒ ‚ n | S( s0 Skip a fixed32 value. Returns the new position.i s Truncated message.( R ( R R R ( ( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt _SkipFixed32) s
c C s t d ƒ ‚ d S( s; Skip function for unknown wire types. Raises an exception.s Tag had invalid wire type.N( R ( R R R ( ( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt _RaiseInvalidWireType1 s c s= t t t t t t t t g ‰ t j ‰ ‡ ‡ f d † } | S( s" Constructs the SkipField function.c s+ t | d d !ƒ ˆ @} ˆ | | | | ƒ S( s Skips a field with the specified tag.
|pos| should point to the byte immediately after the tag.
Returns:
The new position (after the tag value), or -1 if the tag is an end-group
tag (in which case the calling loop should break).
i i ( R{ ( R R R R$ R. ( t WIRETYPE_TO_SKIPPERt
wiretype_mask( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyR` F s ( R| R} R~ R R€ R R‚ R t
TAG_TYPE_MASK( R` ( ( Rƒ R„ sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt
_FieldSkipper6 s l l ÿÿÿÿ l l ÿÿ (B t __doc__t
__author__R7 R t PY3t intt longt google.protobuf.internalR R t google.protobufR R= R< R; t DecodeErrorR R R R( t _DecodeSignedVarintt _DecodeVarint32RD R R0 R3 R: R@ RC RK RG t Int32Decodert Int64Decodert
UInt32Decodert
UInt64Decodert ZigZagDecodet
SInt32Decodert
SInt64DecoderR? t Fixed32DecoderRB t Fixed64Decodert SFixed32Decodert SFixed64Decodert FloatDecodert
DoubleDecodert boolt BoolDecoderRV RW R^ R_ R) R] Re Rr Rz R| R} R~ R R€ R R‚ R† R` ( ( ( sD /usr/lib/python2.7/site-packages/google/protobuf/internal/decoder.pyt O sv
; # O . % / 4 J .