A major overhaul of the whole thing.

It has come to my attention that previously, the project was built on top
of some *very* incorrect assumptions. This patch mostly addresses that.
And while it does NOT leave the project in otherwise working state,
it does weed out most, if not all, of effects of previously incorrect
assumptions, so it can be built the right way from here on forth.

Signed-off-by: Gediminas Jakutis <gediminas@varciai.lt>

1 files changed, 96 insertions, 44 deletions

diff --git a/src/main.c b/src/main.c
index 1050741..352c531 100644
--- a/src/main.c
+++ b/src/main.c
@@ -17,14 +17,18 @@ static char randfile[] = "/dev/urandom";
 
 static struct settings settings = {0};
 
-static struct stream file_in = {.prev_idx = -1, .fd = -1};
-static struct stream file_out = {.prev_idx = -1, .fd = -1, .out = 1};
-
 static int parseargs(int argc, char **argv, struct settings * settings);
-int prime_io_functions(struct settings const * const s, struct stream * const in);
+int load_io_functions(struct settings const * const s, struct stream * const in);
 void printhelp(const char * const name);
-static int stub_get(struct stream * const restrict in, ssize_t idx, struct entry_l * const data);
-static int stub_put(struct stream * const restrict in, ssize_t idx, struct entry_l const * const data);
+struct entry_l *stub_getnext(struct stream * const restrict in);
+static int stub_put(struct stream * const restrict in, struct entry_l const * const data);
+static int stub_split(struct stream * const in, struct stream * const a, struct stream * const b);
+static int stub_flush(struct stream * const in);
+
+/* these need to go AFTER the stub declarations */
+static struct stream file_in = {stream_blank};
+static struct stream file_out = {stream_blank, .out = 1};
+static struct stream file_tmp = {stream_blank, .out = 2};
 
 int main(int argc, char **argv)
 {
@@ -37,21 +41,58 @@ int main(int argc, char **argv)
 		file_in.name = randfile;
 		file_in.out = -1;
 		file_in.n = settings.to;
+		file_in.cached = 1;
+		file_out.cached = 1;
 	} else {
 		file_in.name = settings.filein;
 	}
 
-	ret = prime_io_functions(&settings, &file_in);
-	ret = prime_io_functions(&settings, &file_out);
+	load_io_functions(&settings, &file_in);
 
 	file_out.name = settings.fileout ? settings.fileout : settings.filein;
 	try_s((ret = stream_open(&file_in, &settings)), out);
-	file_out.n = file_in.n;
+	file_out.n = file_in.n - settings.ss;
 	try_s((ret = stream_open(&file_out, &settings)), out);
 
-out:
+	load_io_functions(&settings, &file_out);
+
+	if (settings.access == cached) {
+		try_s((ret = cache_create(&file_in, &settings)), out);
+		try_s((ret = cache_populate(&file_in)), out);
+
+		switch (settings.opmode) {
+		case mode_fetch:
+			if (settings.format == array) {
+				try_s((ret = cache_block_copy(&file_in, &file_out, &settings)), out);
+			} else { /* settings.format == list */
+				try_s((ret = cache_list_copy(&file_in, &file_out, &settings)), out);
+			}
+			break;
+		case mode_generate:
+				try_s((ret = cache_transfer(&file_in, &file_out)), out);
+				break;
+		case mode_normal:
+				/* TODO */
+				;
+		}
+
+		try_s((ret = cache_flush(&file_out)), out);
+
+	} else { /* uncached */
+		/* TODO */
+	}
+
 	stream_close(&file_in);
 	stream_close(&file_out);
+
+	while (0) {
+out:
+		stream_close(&file_in);
+		file_out.out = 2; /* in case of error-exit, just close, don't link */
+		stream_close(&file_out);
+		stream_close(&file_tmp);
+	}
+
 early_out:
 	return ret;
 }
@@ -89,7 +130,7 @@ static int parseargs(int argc, char **argv, struct settings * settings)
 			}
 		} else if (!(strncmp(argv[i], "--num=", 6))) {
 			if (strlen(argv[i]) > 6) {
-				s.to = strtoul(argv[i] + 11, NULL, 10);
+				s.to = strtoul(argv[i] + 6, NULL, 10);
 			} else {
 				goto err;
 			}
@@ -139,45 +180,29 @@ err:
 	return ret;
 }
 
-int prime_io_functions(struct settings const * const s, struct stream * const in)
+int load_io_functions(struct settings const * const s, struct stream * const in)
 {
 	int ret = 0;
 
 	if (in->out == 1) {
 		if (s->format == array) {
-			in->get_element = stub_get;
-			in->put_element = stub_put;
-			in->get_element_cache = cached_get_array;
-			in->put_element_cache = cached_put_array;
+			/* TODO */
 		} else {
-			in->get_element = stub_get;
-			in->put_element = stub_put;
-			in->get_element_cache = cached_get_list;
-			in->put_element_cache = cached_put_list;
+			/* TODO */
 		}
 	} else if (!in->out) { /* reading streams do not support dumping */
 		if (s->format == array) {
-			in->get_element = stub_get;
-			in->put_element = stub_put;
-			in->get_element_cache = stub_get;
-			in->put_element_cache = stub_put;
+			/* TODO */
 		} else {
-			in->get_element = stub_get;
-			in->put_element = stub_put;
-			in->get_element_cache = stub_get;
-			in->put_element_cache = stub_put;
+			/* TODO */
 		}
 	} else { /* data generation streams do not support dumping nor any cache I/O beyond initial data generation */
 		if (s->format == array) {
-			in->get_element = gen_get_array;
-			in->put_element = stub_put;
-			in->get_element_cache = stub_get;
-			in->put_element_cache = stub_put;
+			in->get_next_element_direct = gen_get_array;
+			in->place_next_element_cache = cached_put_array;
 		} else {
-			in->get_element = gen_get_list;
-			in->put_element = stub_put;
-			in->get_element_cache = stub_get;
-			in->put_element_cache = stub_put;
+			in->get_next_element_direct = gen_get_list;
+			in->place_next_element_cache = cached_put_list;
 		}
 	}
 
@@ -188,7 +213,7 @@ void printhelp(const char * const name)
 {
 	printf(	"This is a mergesort program and such\n"
 		"\n"
-		"usage:\t%s [options]\n FILE"
+		"usage:\t%s [OPTION]... FILE"
 		"\n"
 		"Options:\n"
 		" --sort              sort mode (default)\n"
@@ -207,22 +232,49 @@ void printhelp(const char * const name)
 	return;
 }
 
-static int stub_get(struct stream * const restrict in, ssize_t idx, struct entry_l * const data)
+struct entry_l *stub_getnext(struct stream * const restrict in)
 {
+	struct entry_l *ret = NULL;
+
 	(void) in;
-	(void) idx;
-	(void) data;
 
 	rin_warn("stub!");
-	return ENOSYS;
+
+	return ret;
 }
 
-static int stub_put(struct stream * const restrict in, ssize_t idx, struct entry_l const * const data)
+static int stub_put(struct stream * const restrict in, struct entry_l const * const data)
 {
+	int ret = ENOSYS;
+
 	(void) in;
-	(void) idx;
 	(void) data;
 
 	rin_warn("stub!");
-	return ENOSYS;
+
+	return ret;
+}
+
+static int stub_split(struct stream * const in, struct stream * const a, struct stream * const b)
+{
+	int ret = ENOSYS;
+
+	(void) in;
+	(void) a;
+	(void) b;
+
+	rin_warn("stub!");
+
+	return ret;
+}
+
+static int stub_flush(struct stream * const in)
+{
+	int ret = ENOSYS;
+
+	(void) in;
+
+	rin_warn("stub!");
+
+	return ret;
 }