static void fwrite_header(FILE* fp) {
fwrite_no_fail(&MAGIC_CONSTANT, sizeof MAGIC_CONSTANT, 1, fp);
size_t revlen = strlen(BuildInfo_kRevision);
fwrite_no_fail(&revlen, sizeof revlen, 1, fp);
fwrite_no_fail(BuildInfo_kRevision, sizeof(char), revlen, fp);
}
void hh_save(value out_filename) {
CAMLparam1(out_filename);
FILE* fp = fopen(String_val(out_filename), "wb");
fwrite_header(fp);
fwrite_no_fail(&heap_init_size, sizeof heap_init_size, 1, fp);
/*
* Format of the compressed shared memory:
* LZ4 can only work in chunks of 2GB, so we compress each chunk individually,
* and write out each one as
* [compressed size of chunk][uncompressed size of chunk][chunk]
* A compressed size of zero indicates the end of the compressed section.
*/
char* chunk_start = save_start();
int compressed_size = 0;
while (chunk_start < *heap) {
uintptr_t remaining = *heap - chunk_start;
uintptr_t chunk_size = LZ4_MAX_INPUT_SIZE < remaining ?
LZ4_MAX_INPUT_SIZE : remaining;
char* compressed = malloc(chunk_size * sizeof(char));
assert(compressed != NULL);
compressed_size = LZ4_compressHC(chunk_start, compressed,
chunk_size);
assert(compressed_size > 0);
fwrite_no_fail(&compressed_size, sizeof compressed_size, 1, fp);
fwrite_no_fail(&chunk_size, sizeof chunk_size, 1, fp);
fwrite_no_fail((void*)compressed, 1, compressed_size, fp);
chunk_start += chunk_size;
free(compressed);
}
compressed_size = 0;
fwrite_no_fail(&compressed_size, sizeof compressed_size, 1, fp);
fclose(fp);
CAMLreturn0;
}
void hh_save_dep_table(value out_filename) {
CAMLparam1(out_filename);
FILE* fp = fopen(String_val(out_filename), "wb");
fwrite_header(fp);
int compressed_size = 0;
assert(LZ4_MAX_INPUT_SIZE >= DEP_SIZE_B);
char* compressed = malloc(DEP_SIZE_B);
assert(compressed != NULL);
compressed_size = LZ4_compressHC((char*)deptbl, compressed, DEP_SIZE_B);
assert(compressed_size > 0);
fwrite_no_fail(&compressed_size, sizeof compressed_size, 1, fp);
fwrite_no_fail((void*)compressed, 1, compressed_size, fp);
free(compressed);
fclose(fp);
CAMLreturn0;
}
