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On a sizeof(long)==8 machine, ints in range(2**31, 2**32) were getting 

pickled into the signed(!) 4-byte BININT format, so were getting unpickled
again as negative ints.  Repaired that.
Added some minimal docs at the top about what I've learned about the pickle
format codes (little of which was obvious from staring at the code,
although that's partly because all the size-related bugs greatly obscured
the true intent of the code).
Happy side effect:  because save_int() needed to grow a *proper* range
check in order to fix this bug, it can now use the more-efficient BININT1,
BININT2 and BININT formats when the long's value is small enough to fit
in a signed 4-byte int (before this, on a sizeof(long)==8 box it always
used the general INT format for negative ints).
test_cpickle works again on sizeof(long)==8 machines.  test_pickle is
still busted big-time.
This commit is contained in:
Tim Peters 2001-04-10 04:22:00 +00:00
parent e089c68871
commit 3906eb877a
1 changed files with 21 additions and 5 deletions
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26
Modules/cPickle.c
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@ -68,6 +68,20 @@ static char cPickle_module_documentation[] =
#define WRITE_BUF_SIZE 256
/* --------------------------------------------------------------------------
NOTES on format codes.
XXX much more is needed here
Integer types
BININT1 8-bit unsigned integer; followed by 1 byte.
BININT2 16-bit unsigned integer; followed by 2 bytes, little-endian.
BININT 32-bit signed integer; followed by 4 bytes, little-endian.
INT Integer; natural decimal string conversion, then newline.
CAUTION: INT-reading code can't assume that what follows
fits in a Python int, because the size of Python ints varies
across platforms.
LONG Long (unbounded) integer; repr(i), then newline.
-------------------------------------------------------------------------- */
#define MARK '('
#define STOP '.'
@ -904,18 +918,20 @@ save_int(Picklerobject *self, PyObject *args) {
if (!self->bin
#if SIZEOF_LONG > 4
|| (l >> 32)
|| l > 0x7fffffffL
|| l < -0x80000000L
#endif
) {
/* Save extra-long ints in non-binary mode, so that
we can use python long parsing code to restore,
if necessary. */
) {
/* Text-mode pickle, or long too big to fit in the 4-byte
* signed BININT format: store as a string.
*/
c_str[0] = INT;
sprintf(c_str + 1, "%ld\n", l);
if ((*self->write_func)(self, c_str, strlen(c_str)) < 0)
return -1;
}
else {
/* Binary pickle and l fits in a signed 4-byte int. */
c_str[1] = (int)( l & 0xff);
c_str[2] = (int)((l >> 8) & 0xff);
c_str[3] = (int)((l >> 16) & 0xff);