1*3ac0a46fSAndroid Build Coastguard Worker // Copyright 2017 The PDFium Authors 2*3ac0a46fSAndroid Build Coastguard Worker // Use of this source code is governed by a BSD-style license that can be 3*3ac0a46fSAndroid Build Coastguard Worker // found in the LICENSE file. 4*3ac0a46fSAndroid Build Coastguard Worker 5*3ac0a46fSAndroid Build Coastguard Worker #include "fxbarcode/oned/BC_OnedEANChecksum.h" 6*3ac0a46fSAndroid Build Coastguard Worker 7*3ac0a46fSAndroid Build Coastguard Worker #include "core/fxcrt/fx_extension.h" 8*3ac0a46fSAndroid Build Coastguard Worker EANCalcChecksum(const ByteString & contents)9*3ac0a46fSAndroid Build Coastguard Workerint32_t EANCalcChecksum(const ByteString& contents) { 10*3ac0a46fSAndroid Build Coastguard Worker int32_t odd = 0; 11*3ac0a46fSAndroid Build Coastguard Worker int32_t even = 0; 12*3ac0a46fSAndroid Build Coastguard Worker size_t parity = 1; 13*3ac0a46fSAndroid Build Coastguard Worker for (size_t i = contents.GetLength(); i > 0; i--) { 14*3ac0a46fSAndroid Build Coastguard Worker if (parity % 2) 15*3ac0a46fSAndroid Build Coastguard Worker odd += FXSYS_DecimalCharToInt(contents[i - 1]); 16*3ac0a46fSAndroid Build Coastguard Worker else 17*3ac0a46fSAndroid Build Coastguard Worker even += FXSYS_DecimalCharToInt(contents[i - 1]); 18*3ac0a46fSAndroid Build Coastguard Worker parity++; 19*3ac0a46fSAndroid Build Coastguard Worker } 20*3ac0a46fSAndroid Build Coastguard Worker return (10 - (odd * 3 + even) % 10) % 10; 21*3ac0a46fSAndroid Build Coastguard Worker } 22