tools: add cmd/tools/gg_split_memdump_to_frames.vsh to ease working with memdump.bin files generated by gg programs (split by frames)

cmd/tools/gg_split_memdump_to_frames.vsh

@@ -0,0 +1,42 @@
+#!/usr/bin/env -S v -raw-vsh-tmp-prefix tmp
+
+module main
+
+import os
+import log
+
+fn write_chunk(n int, min_size int, original string, start int, end int) {
+	size := end - start
+	if size < min_size {
+		return
+	}
+	frame_file := 'frame_${n:06}.bin'
+	log.warn('writing ${frame_file}, from start: ${start:9}, to end: ${end:9} | size: ${size:9} >= ${min_size:9}, memuse: ${gc_memory_use()}')
+	os.write_file(frame_file, original#[start..end]) or { log.error(err.str()) }
+}
+
+fn main() {
+	log.info('Start.')
+	fpath := os.args[2] or { 'memdump.bin' }
+	separator := os.args[3] or { '@@ gg_memory_trace_frame' }
+	min_size := os.args[1] or { '${separator.len}' }.int()
+	log.info('Splitting chunk min_size (arg 1): ${min_size}, file (arg 2): ${fpath}, by string separator (arg 3): `${separator}` ...')
+	log.info('Memory use before reading: ${gc_memory_use()}')
+	original := os.read_file(fpath)!
+	log.info('file size: ${original.len}')
+	log.info('Memory use after reading: ${gc_memory_use()}')
+	mut n := 0
+	for start := 0; start < original.len; {
+		gc_collect()
+		idx := original.index_after_(separator, start + separator.len) // ensure that we advance each time
+		if idx < 0 {
+			write_chunk(n, min_size, original, start, original.len)
+			break
+		}
+		write_chunk(n, min_size, original, start, idx)
+		start = idx
+		n++
+	}
+	log.info('Memory use after processing: ${gc_memory_use()}')
+	log.info('Done.')
+}