When we have a stable output buffer take the single-pass shortcut.
It is okay to return `dstSizeTooSmall` if the output buffer isn't
big enough, because we know it will never grow.
Sets these parameters in ZSTD_compress2() then resets them to their
orignal values after the compression call.
An alternative design could be to add a flush mode `ZSTD_e_singlePass`
which implies `ZSTD_c_stable{In,Out}Buffer` but only for a single
compression call, by directly setting the applied parameters. I've opted
for the smaller change, but this is open for discussion.
Previously only `nbWorkers` was set. Set all parameters, because that is
what is expected. This is needed for the `ZSTD_c_stable{In,Out}Buffer`
parameters.
Makefile now automatically detects modifications of compilation flags,
and produce object files in directories dedicated to this compilation flags.
This makes it possible, for example, to compile libzstd with different DEBUGLEVEL.
Object files sharing the same configration will be generated into their dedicated directories.
Also : new compilation variables
- DEBUGLEVEL : select the debug level (assert & traces) inserted during compilation (default == 0 == release)
- HASH : select a hash function to differentiate configuration (default == md5sum)
- BUILD_DIR : skip the hash stage, store object files into manually specified directory
%.o object files generated for dynamic library
must be different from those generated for static library.
Due to this difference, %.o were so far only generated for the static library.
The dynamic library was rebuilt from %.c source.
This meant that, for every minor change, the entire dynamic library had to be rebuilt.
This is fixed in this PR :
only the modified %.c source get rebuilt.
That was a subtle one :
VPATH is affecting search for both %.c source and %.o object files.
This meant that, when an object file already exists in lib/,
it's used in programs/,
even though programs/ is supposed to generate its own %.o object files.
With the new vpath directive, this is no longer the case :
the search is only activated for %.c source files.
Now, local programs/%.o are always generated
even if equivalent ones are already created in lib/.
It more clearly guarantees that lib/ and programs/ can use different compilation directives
without mixing resulting %.o object files.
Nick Terrell