as suggested in #1441.
generally U32 and unsigned are the same thing,
except when they are not ...
case : 32-bit compilation for MIPS (uint32_t == unsigned long)
A vast majority of transformation consists in transforming U32 into unsigned.
In rare cases, it's the other way around (typically for internal code, such as seeds).
Among a few issues this patches solves :
- some parameters were declared with type `unsigned` in *.h,
but with type `U32` in their implementation *.c .
- some parameters have type unsigned*,
but the caller user a pointer to U32 instead.
These fixes are useful.
However, the bulk of changes is about %u formating,
which requires unsigned type,
but generally receives U32 values instead,
often just for brevity (U32 is shorter than unsigned).
These changes are generally minor, or even annoying.
As a consequence, the amount of code changed is larger than I would expect for such a patch.
Testing is also a pain :
it requires manually modifying `mem.h`,
in order to lie about `U32`
and force it to be an `unsigned long` typically.
On a 64-bit system, this will break the equivalence unsigned == U32.
Unfortunately, it will also break a few static_assert(), controlling structure sizes.
So it also requires modifying `debug.h` to make `static_assert()` a noop.
And then reverting these changes.
So it's inconvenient, and as a consequence,
this property is currently not checked during CI tests.
Therefore, these problems can emerge again in the future.
I wonder if it is worth ensuring proper distinction of U32 != unsigned in CI tests.
It's another restriction for coding, adding more frustration during merge tests,
since most platforms don't need this distinction (hence contributor will not see it),
and while this can matter in theory, the number of platforms impacted seems minimal.
Thoughts ?
it was invoking ZSTD_initCStream_advanced() with pledgedSrcSize==0 and contentSizeFlag=1
which means "empty"
while the intention was to mean "unknown".
The contentSizeFlag==1 is new, it is a consequence of setting this value to 1 by default.
The solution selected here is to pass ZSTD_CONTENTSIZE_UNKNOWN to mean "unknown".
So contentSizeFlag remains set (it wasn't in previous versions).
UTIL_getFileSize() used to return zero on failure.
This made it impossible to distinguish a failure from a genuine empty file.
Both cases where coalesced.
Adding UTIL_FILESIZE_UNKNOWN constant has many consequences on user code,
since in many places, the `0` was assumed to mean "error".
This is no longer the case, and the error code must be actively checked.
for easier invocation.
- no longer expose frequency timer :
it's either useless, or stored internally in a static variable (init is only necessary once).
- UTIL_getTime() provides result by function return.
supporting function for bufferless streaming API (ZSTD_decompressContinue())
makes it possible to correctly size a round buffer for decoding using this API.
also : added field blockSizeMax within ZSTD_frameHeader,
as it's a necessary information to know when to restart at beginning of decoding buffer.
now ZSTD_customCMem is promoted as new default.
Advantages : ZSTD_customCMem = { NULL, NULL, NULL},
so it's natural default after a memset.
ZSTD_customCMem is public constant
(defaultCustomMem was private only).
Also : makes it possible to introduce ZSTD_calloc(),
which can now default to stdlib's calloc()
when it detects system default.
Fixed zlibwrapper which depended on defaultCustomMem.
It now only uses compressionParameters as argument.
It produces many changes throughout user code,
though hopefully they tend to be simple :
just provide the cParams part from existing ZSTD_parameters.
Some programs might depend on ZSTD_createCDict_advanced() to pass frame parameters.
This change will force them to revisit this strategy and fix it,
since frame parameters are effectively silently ignored in current version.
