We have seen how to define a Mythryl library and compile it using Mythryl’s make function.
Using this approach, each time the make command is issued, all source files contributing to the library are checked and their last-modified times compared with the last-modified time of the library proper; if the compiled library code is out of date, the logically minimum amount of recompilation needed is done to reconstruct it.
This is exactly the behavior one wants during development, but scanning the source files does take time, and for production deployment of a library, say on an embedded Linux box with limited memory, one may not even want to have the source code around.
Mythryl supplies the freeze function for such production deployment. Freezing a library compiles it into a binary freezefile form in which the source code is no longer needed. When the Mythryl make command sees such a freezefile, it does not even look for the library sourcefiles, or even the library .lib file.
Continuing the previous example, here is how we would construct a freezefile for it:
linux$ my
eval: make "factor.lib";
src/app/makelib/main/makelib-g.pkg: Running .lib file factor.lib
parse/libfile-parser-g.pkg: Reading make file factor.lib on behalf of <toplevel>
makelib/compilable/thawedlib-tome.pkg: Parsing source file factor.api
makelib/compilable/thawedlib-tome.pkg: Parsing source file factor.pkg
makelib/compilable/thawedlib-tome.pkg: Parsing source file main.pkg
.../compile/compile-in-dependency-order-g.pkg: Compiling source file factor.api to object file factor.api.compiled
.../compile/compile-in-dependency-order-g.pkg: Compiling source file factor.pkg to object file factor.pkg.compiled
.../compile/compile-in-dependency-order-g.pkg: Compiling source file main.pkg to object file main.pkg.compiled
src/app/makelib/main/makelib-g.pkg: New names added.
eval: freeze "factor.lib";
src/app/makelib/main/makelib-g.pkg: Running .lib file factor.lib
parse/libfile-parser-g.pkg: Reading make file factor.lib on behalf of <toplevel>
.../compile/compile-in-dependency-order-g.pkg: Loading factor.api
.../compile/compile-in-dependency-order-g.pkg: Loading factor.pkg
.../compile/compile-in-dependency-order-g.pkg: Loading main.pkg
.../freezefile/freezefile-g.pkg: Creating library factor.lib.frozen
eval: ^D
linux$ ls -l
-rw-r--r-- 1 cynbe cynbe 48 2009-03-09 02:19 factor.api
-rw-r--r-- 1 cynbe cynbe 283 2009-03-09 02:19 factor.api.compiled
-rw-r--r-- 1 cynbe cynbe 172 2009-03-09 02:28 factor.lib
-rw-r--r-- 1 cynbe cynbe 5409 2009-03-12 13:57 factor.lib.frozen
-rw-r--r-- 1 cynbe cynbe 488 2009-03-09 02:18 factor.pkg
-rw-r--r-- 1 cynbe cynbe 1107 2009-03-09 02:18 factor.pkg.compiled
-rw-r--r-- 1 cynbe cynbe 1161 2009-03-09 02:34 main.pkg
-rw-r--r-- 1 cynbe cynbe 3391 2009-03-09 02:34 main.pkg.compiled
Here the new factor.lib.frozen library archive file logically replaces all the other files shown, including the four .compiled object code files, the .api and .pkg source files and the master factor.lib library definition file. All of these files may now be removed if desired.
To load the freezefile into Mythryl you still do make "factor.lib" but as long as factor.lib.frozen exists, makelib does not even look for the factor.lib file.
(Of course, as often as not, the factor library is listed as needed by some other .lib file and is pulled in automatically as part of the make without explicit mention on your part.)
To unfreeze the library, just remove the factor.lib.frozen file. Mythryl’s make will then revert to its usual behavior of checking all sourcefile timestamps and automatically recompiling as needed.