--- /dev/null
+////////////////////////////////////////////////////////////////////////////////\r
+\r
+// Author: Andy Rushton\r
+// Copyright: (c) Southampton University 1999-2004\r
+// (c) Andy Rushton 2004-2009\r
+// License: BSD License, see ../docs/license.html\r
+\r
+////////////////////////////////////////////////////////////////////////////////\r
+#include "persistent_int.hpp"\r
+\r
+////////////////////////////////////////////////////////////////////////////////\r
+// Macro for mapping either endian data onto little-endian addressing to make\r
+// my life easier in writing this code! I think better in little-endian mode\r
+// so the macro does nothing in that mode but maps little-endian onto\r
+// big-endian addressing in big-endian mode\r
+// TODO - make this compile-time configurable so it's more efficient\r
+\r
+#define INDEX(index) ((context.little_endian()) ? (index) : ((bytes) - (index) - 1))\r
+\r
+////////////////////////////////////////////////////////////////////////////////\r
+// Integer types\r
+// format: {size}{byte}*size\r
+// size can be zero!\r
+//\r
+// A major problem is that integer types may be different sizes on different\r
+// machines or even with different compilers on the same machine (though I\r
+// haven't come across that yet). Neither the C nor the C++ standards specify\r
+// the size of integer types. Dumping an int on one machine might dump 16\r
+// bits. Restoring it on another machine might try to restore 32 bits. These\r
+// functions must therefore handle different type sizes. It does this by\r
+// writing the size to the file as well as the data, so the restore can\r
+// therefore know how many bytes to restore independent of the type size.\r
+//\r
+// In fact, the standard does not even specify the size of char (true! And\r
+// mind-numbingly stupid...). However, to be able to do anything at all, I've\r
+// had to assume that a char is 1 byte.\r
+\r
+static void dump_unsigned(stlplus::dump_context& context, unsigned bytes, unsigned char* data)\r
+ throw(stlplus::persistent_dump_failed)\r
+{\r
+ // first skip zero bytes - this may reduce the data to zero bytes long\r
+ unsigned i = bytes;\r
+ while(i >= 1 && data[INDEX(i-1)] == 0)\r
+ i--;\r
+ // put the remaining size\r
+ context.put((unsigned char)i);\r
+ // and put the bytes\r
+ while(i--)\r
+ context.put(data[INDEX(i)]);\r
+}\r
+\r
+static void dump_signed(stlplus::dump_context& context, unsigned bytes, unsigned char* data)\r
+ throw(stlplus::persistent_dump_failed)\r
+{\r
+ // first skip all-zero or all-one bytes but only if doing so does not change the sign\r
+ unsigned i = bytes;\r
+ if (data[INDEX(i-1)] < 128)\r
+ {\r
+ // positive number so discard leading zeros but only if the following byte is positive\r
+ while(i >= 2 && data[INDEX(i-1)] == 0 && data[INDEX(i-2)] < 128)\r
+ i--;\r
+ }\r
+ else\r
+ {\r
+ // negative number so discard leading ones but only if the following byte is negative\r
+ while(i >= 2 && data[INDEX(i-1)] == 255 && data[INDEX(i-2)] >= 128)\r
+ i--;\r
+ }\r
+ // put the remaining size\r
+ context.put((unsigned char)i);\r
+ // and put the bytes\r
+ while(i--)\r
+ context.put(data[INDEX(i)]);\r
+}\r
+\r
+static void restore_unsigned(stlplus::restore_context& context, unsigned bytes, unsigned char* data)\r
+ throw(stlplus::persistent_restore_failed)\r
+{\r
+ // get the dumped size from the file\r
+ unsigned dumped_bytes = (unsigned)context.get();\r
+ // zero fill any empty space\r
+ unsigned i = bytes;\r
+ for (; i > dumped_bytes; i--)\r
+ data[INDEX(i-1)] = 0;\r
+ // restore the dumped bytes but discard any that don't fit\r
+ while(i--)\r
+ {\r
+ int ch = context.get();\r
+ if (i < bytes)\r
+ data[INDEX(i)] = (unsigned char)ch;\r
+ else\r
+ throw stlplus::persistent_restore_failed(std::string("integer overflow"));\r
+ }\r
+}\r
+\r
+static void restore_signed(stlplus::restore_context& context, unsigned bytes, unsigned char* data)\r
+ throw(stlplus::persistent_restore_failed)\r
+{\r
+ // get the dumped size from the file\r
+ unsigned dumped_bytes = (unsigned)context.get();\r
+ // restore the dumped bytes but discard any that don't fit\r
+ unsigned i = dumped_bytes;\r
+ while(i--)\r
+ {\r
+ int ch = context.get();\r
+ if (i < bytes)\r
+ data[INDEX(i)] = (unsigned char)ch;\r
+ else\r
+ throw stlplus::persistent_restore_failed(std::string("integer overflow"));\r
+ }\r
+ // sign extend if the dumped integer was smaller\r
+ if (dumped_bytes < bytes)\r
+ {\r
+ if (data[INDEX(dumped_bytes-1)] < 128)\r
+ {\r
+ // positive so zero fill\r
+ for (i = dumped_bytes; i < bytes; i++)\r
+ data[INDEX(i)] = 0;\r
+ }\r
+ else\r
+ {\r
+ // negative so one fill\r
+ for (i = dumped_bytes; i < bytes; i++)\r
+ data[INDEX(i)] = 0xff;\r
+ }\r
+ }\r
+}\r
+\r
+////////////////////////////////////////////////////////////////////////////////\r
+// exported functions\r
+\r
+// char is dumped and restored as an unsigned char because the signedness of char is not defined and can vary\r
+void stlplus::dump_char(stlplus::dump_context& context, const char& data) throw(stlplus::persistent_dump_failed)\r
+{\r
+ context.put((unsigned char)data);\r
+}\r
+\r
+void stlplus::restore_char(restore_context& context, char& data) throw(stlplus::persistent_restore_failed)\r
+{\r
+ data = (char)(unsigned char)context.get();\r
+}\r
+\r
+void stlplus::dump_signed_char(stlplus::dump_context& context, const signed char& data) throw(stlplus::persistent_dump_failed)\r
+{\r
+ context.put((unsigned char)data);\r
+}\r
+\r
+void stlplus::restore_signed_char(restore_context& context, signed char& data) throw(stlplus::persistent_restore_failed)\r
+{\r
+ data = (signed char)(unsigned char)context.get();\r
+}\r
+\r
+void stlplus::dump_unsigned_char(stlplus::dump_context& context, const unsigned char& data) throw(stlplus::persistent_dump_failed)\r
+{\r
+ context.put((unsigned char)data);\r
+}\r
+\r
+void stlplus::restore_unsigned_char(restore_context& context, unsigned char& data) throw(stlplus::persistent_restore_failed)\r
+{\r
+ data = (signed char)(unsigned char)context.get();\r
+}\r
+\r
+void stlplus::dump_short(stlplus::dump_context& context, const short& data) throw(stlplus::persistent_dump_failed)\r
+{\r
+ ::dump_signed(context, sizeof(short), (unsigned char*)&data);\r
+}\r
+\r
+void stlplus::restore_short(restore_context& context, short& data) throw(stlplus::persistent_restore_failed)\r
+{\r
+ ::restore_signed(context, sizeof(short),(unsigned char*)&data);\r
+}\r
+\r
+void stlplus::dump_unsigned_short(stlplus::dump_context& context, const unsigned short& data) throw(stlplus::persistent_dump_failed)\r
+{\r
+ ::dump_unsigned(context, sizeof(unsigned short), (unsigned char*)&data);\r
+}\r
+\r
+void stlplus::restore_unsigned_short(restore_context& context, unsigned short& data) throw(stlplus::persistent_restore_failed)\r
+{\r
+ ::restore_unsigned(context, sizeof(unsigned short),(unsigned char*)&data);\r
+}\r
+\r
+void stlplus::dump_int(stlplus::dump_context& context, const int& data) throw(stlplus::persistent_dump_failed)\r
+{\r
+ ::dump_signed(context, sizeof(int), (unsigned char*)&data);\r
+}\r
+\r
+void stlplus::restore_int(restore_context& context, int& data) throw(stlplus::persistent_restore_failed)\r
+{\r
+ ::restore_signed(context, sizeof(int),(unsigned char*)&data);\r
+}\r
+\r
+void stlplus::dump_unsigned(stlplus::dump_context& context, const unsigned& data) throw(stlplus::persistent_dump_failed)\r
+{\r
+ ::dump_unsigned(context, sizeof(unsigned), (unsigned char*)&data);\r
+}\r
+\r
+void stlplus::restore_unsigned(restore_context& context, unsigned& data) throw(stlplus::persistent_restore_failed)\r
+{\r
+ ::restore_unsigned(context, sizeof(unsigned),(unsigned char*)&data);\r
+}\r
+\r
+void stlplus::dump_long(stlplus::dump_context& context, const long& data) throw(stlplus::persistent_dump_failed)\r
+{\r
+ ::dump_signed(context, sizeof(long), (unsigned char*)&data);\r
+}\r
+\r
+void stlplus::restore_long(restore_context& context, long& data) throw(stlplus::persistent_restore_failed)\r
+{\r
+ ::restore_signed(context, sizeof(long),(unsigned char*)&data);\r
+}\r
+\r
+void stlplus::dump_unsigned_long(stlplus::dump_context& context, const unsigned long& data) throw(stlplus::persistent_dump_failed)\r
+{\r
+ ::dump_unsigned(context, sizeof(unsigned long), (unsigned char*)&data);\r
+}\r
+\r
+void stlplus::restore_unsigned_long(restore_context& context, unsigned long& data) throw(stlplus::persistent_restore_failed)\r
+{\r
+ ::restore_unsigned(context, sizeof(unsigned long),(unsigned char*)&data);\r
+}\r
+\r
+////////////////////////////////////////////////////////////////////////////////\r
projects / chaz / yoink / blobdiff