AddZdjZ ddlmcmZdZddl Z ddl Z GddZ dd Zd Zd Zd Zd ZdZdZej*ej,gej.ej0gej2ej4gej6ej8gej:ej<gdZiZ djD]9Z!dddddjEe jFe!dZ$e$-e$e vs2de!ze e$<;e de d<[![$dZ%dZ&dZ'y#e$r ddl m ZdZYwxYw)aycrcmod is a Python module for gererating objects that compute the Cyclic Redundancy Check. Any 8, 16, 24, 32, or 64 bit polynomial can be used. The following are the public components of this module. Crc -- a class that creates instances providing the same interface as the algorithms in the hashlib module in the Python standard library. These instances also provide a method for generating a C/C++ function to compute the CRC. mkCrcFun -- create a Python function to compute the CRC using the specified polynomial and initial value. This provides a much simpler interface if all you need is a function for CRC calculation. z mkCrcFun Crc NT) _crcfunpyFcFeZdZdZd dZdZd dZdZdZdZ d Z d d Z y)CrcaCompute a Cyclic Redundancy Check (CRC) using the specified polynomial. Instances of this class have the same interface as the algorithms in the hashlib module in the Python standard library. See the documentation of this module for examples of how to use a Crc instance. The string representation of a Crc instance identifies the polynomial, initial value, XOR out value, and the current CRC value. The print statement can be used to output this information. If you need to generate a C/C++ function for use in another application, use the generateCode method. If you need to generate code for another language, subclass Crc and override the generateCode method. The following are the parameters supplied to the constructor. poly -- The generator polynomial to use in calculating the CRC. The value is specified as a Python integer. The bits in this integer are the coefficients of the polynomial. The only polynomials allowed are those that generate 8, 16, 24, 32, or 64 bit CRCs. initCrc -- Initial value used to start the CRC calculation. This initial value should be the initial shift register value XORed with the final XOR value. That is equivalent to the CRC result the algorithm should return for a zero-length string. Defaults to all bits set because that starting value will take leading zero bytes into account. Starting with zero will ignore all leading zero bytes. rev -- A flag that selects a bit reversed algorithm when True. Defaults to True because the bit reversed algorithms are more efficient. xorOut -- Final value to XOR with the calculated CRC value. Used by some CRC algorithms. Defaults to zero. c|syt|||\}}}|dz|_||_||_||_||_t |||||\}}||_||_|j|_ y)N) _verifyParams digest_sizeinitCrcxorOutpolyreverse _mkCrcFun_crctablecrcValue) selfr r revr initializesizeBitscrcfunrs /lib/third_party/gcloud_crcmod/python3/crcmod.py__init__z Crc.__init__Ysv &3D'6&J#7F#Q;    #D(GS&I    cg}|jd|jz|jd|jzd|jdzz}|jd||jzz|jd||j zz|jd||j zzdj|S) Nz poly = 0x%Xz reverse = %s0x%%0%dXz initCrc = %sz xorOut = %sz crcValue = %s )appendr r r r r rjoin)rlstfmts r__str__z Crc.__str__ms =499,- >DLL01D,,Q./ ?cDLL&89: ?cDKK&789 ?cDMM&9:;yy~rNcVtdd}|j|_|j|_|j|_|j|_|j |_|j|_|j|_|j|_||j||S)a Create a new instance of the Crc class initialized to the same values as the original instance. The current CRC is set to the initial value. If a string is provided in the optional arg parameter, it is passed to the update method. NF)r r) rrr r r rrr r update)rargns rnewzCrc.newws Te ,(( LL ;;**\\ LL  ? HHSMrcH|j}|j|_|S)zCreate a new instance of the Crc class initialized to the same values as the original instance. The current CRC is set to the current value. This allows multiple CRC calculations using a common initial string. )r'r)rcs rcopyzCrc.copys HHJ]] rcF|j||j|_y)z_Update the current CRC value using the string specified as the data parameter. N)rr)rdatas rr$z Crc.updates $ 6 rc|j}|j}g}|dkDr$|j|dz|dz }|dz}|dkDr$|jt |S)zReturn the current CRC value as a string of bytes. The length of this string is specified in the digest_size attribute. rr)r rrr bytesrr&crcr s rdigestz Crc.digestsd   mm!e JJsTz "(C FA!e Szrc|j}|j}g}|dkDr'|jd|dzz|dz }|dz}|dkDr'|jdj |S)zReturn the current CRC value as a string of hex digits. The length of this string is twice the digest_size attribute. rz%02Xr.rr/)r rrr rr1s r hexdigestz Crc.hexdigestsm   mm!e JJvt, -(C FA!e wws|rc |d}|d|jz}|dk(rd}d|z}|jdk(rd}n&|jrd }nd|jdz z}d |z}d d |jzz}|jd kr|dz}n|dz}ddd d d d|j} g} t|jD]2\} } | | zdk(r| j d| j || z4d|j z} |jr| dz} |j rd|dd|j zz}|}nd}d}|jdk(r|jr|dz }n|dz }|||||zdj| | ||d}|jt|zy)a(Generate a C/C++ function. functionName -- String specifying the name of the function. out -- An open file-like object with a write method. This specifies where the generated code is written. dataType -- An optional parameter specifying the data type of the input data to the function. Defaults to UINT8. crcType -- An optional parameter specifying the data type of the CRC value. Defaults to one of UINT8, UINT16, UINT32, or UINT64 depending on the size of the CRC value. NUINT8r zUINT%dr/ztable[*data ^ (%s)crc]z#table[*data ^ (%s)crc] ^ (crc >> 8)z,table[*data ^ (%%s)(crc >> %d)] ^ (crc << 8)rrzU,zULL,)r/rr;rrz zpolynomial: 0x%Xz, bit reverse algorithmz crc = crc ^ %s;r5r<z crc = crc & 0xFFFFFFU;)dataTypecrcTypenamecrcAlgorcrcTabler preCondition postCondition) r r enumeraterrr r rwrite _codeTemplate)r functionNameoutr>r?sizerAshiftr!r&r ivalr rCrDparmss r generateCodezCrc.generateCodes  H ?T%%%DrzoG   q /H \\=Ht''!+,EEMHAd.../   q *C,CAa1 %d&6&6 7 +FAsA!| 8$ JJsSy !, "DII- <<33D ;;2c#2h6LML(MLM   q || >> !?? "!!H,)+   -%'(r)r=TrTN)NN) __name__ __module__ __qualname____doc__rr"r'r*r$r3r6rOrrrr6s1!D%(&7  T)rrcHt|||\}}}t|||||dS)aReturn a function that computes the CRC using the specified polynomial. poly -- integer representation of the generator polynomial initCrc -- default initial CRC value rev -- when true, indicates that the data is processed bit reversed. xorOut -- the final XOR value The returned function has the following user interface def crcfun(data, crc=initCrc): r)rr)r r rr rs rmkCrcFunrW s1#0gv"FXw T8Wc6 :1 ==rc`d}dD]}d|z}|dz}||cxkr |ks|cSt|)Nz8The degree of the polynomial must be 8, 16, 24, 32 or 64rr9r:@r/r) ValueError)r msgr&lowhighs r _verifyPolyr`'sF DC d1u $  H  S/rcJd}t|D]}|dz|dzz}|dz }|S)Nrr/range)xr&yrLs r_bitrevrf3s7 A 1X !VA  F Hrcvd|dz z}tdD]}||zr |dz|z }|dz}d|zdz }||z}|S)Nr/rrb)r2r r&maskrLs r_bytecrcri?sX qs8D 1X :!8t#C(C  qDA:D *C JrcftdD]}|dzr |dz |z }|dz }d|zdz }||z}|S)Nrr/rb)r2r r&rLrhs r _bytecrc_rrkJsK 1X 7!8t#C(C  qDA:D *C Jrc|d|zdz }||z}tdDcgc]}t||dz z||}}|Scc}w)Nr/r)rcrir r&rhrLrs r_mkTablero\sK qDA:D $;D05c ; 1Xa!A#htA & E ; L .crcfunstS%( (rc$|||z |z SrPrU)r,r2rrur s rrz_mkCrcFun..crcfunsCfslE:: :r)rq_sizeMapro_usingExtensionstructpack_sizeToTypeCode) r rr rr tableList_fun_tablers ` rrrs tX. !!$T8, !!$ F_X6CC {$F ) 9 %F ; 9 raK// Automatically generated CRC function // %(poly)s %(crcType)s %(name)s(%(dataType)s *data, int len, %(crcType)s crc) { static const %(crcType)s table[256] = {%(crcTable)s }; %(preCondition)s while (len > 0) { crc = %(crcAlgor)s; data++; len--; }%(postCondition)s return crc; } )r=Tr)(rTsplit__all__ gcloud_crcmod.python3._crcfunextpython3 _crcfunext_crcfunrx ImportErrorgcloud_crcmod.python3rsysryrrWr`rfrirkrorq_crc8_crc8r_crc16_crc16r_crc24_crc24r_crc32_crc32r_crc64_crc64rrwr{typeCodegetcalcsizerJrrrGrUrrrsV.   EG 66O T)T)n>4  $  -- ( ..'// * ..'// * ..'// * ..'// *  !!#H2r " & &vx'@ FD D7 '( 2$ &b) d '2, S :Os D D/.D/