Allow setting dynamic space size easily at build time, fix #112.

INSTALL.md

@@ -62,3 +62,12 @@ It's possible to pick [ccl](http://ccl.clozure.com/) rather than SBCL when
 compiling pgloader:
 
     make CL=ccl
+
+## Building pgloader for use in low RAM environments
+
+It's possible to tweak the size of RAM pgloader will use in its binary
+image, ac compile time. This defaults to 4 GB.
+
+    make DYNSIZE=1024
+    
+Now the `./build/bin/pgloader` that you get only uses 1GB.

Makefile

@@ -5,6 +5,9 @@ VERSION    = 3.1.0
 # use either sbcl or ccl
 CL	   = sbcl
 
+# default to 4096 MB of RAM size in the image
+DYNSIZE    = 4096
+
 LISP_SRC   = $(wildcard src/*lisp) \
              $(wildcard src/pgsql/*lisp) \
              $(wildcard src/sources/*lisp) \
@@ -111,7 +114,7 @@ $(PGLOADER): $(MANIFEST) $(BUILDAPP) $(LISP_SRC)
                          --load-system $(APP_NAME)               \
                          --load src/hooks.lisp                   \
                          --entry pgloader:main                   \
-                         --dynamic-space-size 4096               \
+                         --dynamic-space-size $(DYNSIZE)         \
                          $(COMPRESS_CORE_OPT)                    \
                          --output $@
 
@@ -123,7 +126,7 @@ pgloader-standalone:
                        --require sb-rotate-byte                \
                        --load-system pgloader                  \
                        --entry pgloader:main                   \
-                       --dynamic-space-size 4096               \
+                       --dynamic-space-size $(DYNSIZE)         \
                        --compress-core                         \
                        --output $(PGLOADER)