Added `cmp_find()` `cmp_find_many()` in "comp.c"/"comp.h".

Added main TODOs in main(), regarding setting up threadpool, dispatches, consolidation, process return value on match fails, etc.

Fortune for naka's current commit: Small blessing − 小吉

include/comp.h

@@ -0,0 +1,17 @@
+#ifndef _COMP_H
+#define _COMP_H
+
+#include <macros.h>
+#include <ints.h>
+
+/// Find `needle` in `haystack`, sets the start of `needle`'s `origin` in `haystack`'s to `pos` and returns `true` if a match is found, otherwise returns false.
+bool cmp_find(const map_t *pIN needle, const map_t *pIN haystack, usize *pOUT pos);
+/// Check `needle` against `nhaystacks` number of haystack maps, store the offset in `sizes[n]` where `n` is the haystack number.
+/// `sizes` must be at least `nhaystacks` long. The haystacks themselves are expected to be of type `const map_t* pIN`
+/// Returns `-1` if all haystacks passed match, otherwise returns the index of the haystack that failed.
+///
+/// # Panics
+/// Will `FATAL` if any of the haystack pointers are `NULL`
+int cmp_find_many(usize nhaystacks; const map_t *pIN needle, usize sizes[pOUT nhaystacks], usize nhaystacks, ...);
+
+#endif /* _COMP_H */

include/macros.h

@@ -44,10 +44,12 @@
 // Used like: `int *pOUT output, const int *pIN input`
 #define pOUT restrict
 #define pIN const restrict
+#define pINOUT restrict
 
 // Used like: `int _OUT output, const int _IN input`
 #define _IN *pIN
 #define _OUT *pOUT
+#define _INOUT *pINOUT
 
 // Type macros
 

include/map.h

@@ -14,12 +14,16 @@ typedef enum mm_err {
 	MAP_ERR_OPEN,
 	MAP_ERR_CLOSE,
 	MAP_ERR_STAT,
+	MAP_ERR_ADVISE,
 } map_result_t;
 
 typedef union memory_map {
 	// Common
 	struct {
+		union {
 			void* origin;
+			u8* area;
+		};
 		usize len;
 	};
 	// Specific to anon / file
@@ -42,6 +46,7 @@ map_result_t map_fd(int fd, bool write, usize size, off_t offset, map_t *pOUT ma
 map_result_t map_file(const char* file, bool write, usize size, off_t offset, map_t *pOUT map);
 map_result_t map_anon(void* ptr, usize len, map_t *pOUT map);
 map_result_t map_free(map_t map);
+map_result_t map_preload(map_t *pINOUT map, bool random);
 
 const char* map_error_str(map_result_t res);
 

include/project.h

@@ -35,6 +35,10 @@
 #define PROG_RET_MAP_HAYSTACK_N_FAILED(h) ((h) << 2)
 // `h` is the number in argv[] of the haystack file
 #define PROG_RET_UNMAP_HAYSTACK_N_FAILED(h) (((h) << 2) | 1)
+// Match of haystack number `h` failed.
+#define PROG_RET_MAP_HAYSTACK_N_FAILED(h) ((h) << 2 | 2)
+// Bitwise OR this with the number(s) of the haystack that match failed. It must not exceed INT_MAX-1
+#define PROG_RET_MAP_HAYSTACK_FAILED AS((AS(INT_MAX, u64) >> 1lu) ^ AS(INT_MAX, u64), int)
 // Unmapping of argv[1] failed
 #define PROG_RET_UNMAP_NEEDLE_FAILED 3
 // Internal error

src/comp.c

@@ -0,0 +1,38 @@
+#define _GNU_SOURCE
+
+#include <stdarg.h>
+#include <string.h>
+
+#include <macros.h>
+#include <ints.h>
+#include <map.h>
+
+
+bool cmp_find(const map_t *pIN needle, const map_t *pIN haystack, usize *pOUT pos)
+{
+	u8* start;
+	u8* substr = memmem(start = haystack->origin, haystack->len,
+			needle->origin, needle->len);
+	if(!substr) return false;
+	debug_assert(substr > start);
+	*pos = (usize) (substr - start);
+	return true;
+}
+
+int cmp_find_many(usize nhaystacks; const map_t *pIN needle, usize sizes[pOUT nhaystacks], usize nhaystacks, ...)
+{
+	va_list v_haystacks;
+	va_start(v_haystacks, nhaystacks);
+
+	const map_t* pINOUT haystack;
+	for(usize i=0;i<nhaystacks;i++)
+	{
+		usize *pOUT size = sizes + i;
+		haystack = va_arg(v_haystacks, const map_t* pIN);
+		if(!haystack || !haystack->origin) FATAL("haystack %lu was null or its origin was null", i);
+		if(!cmp_find(needle, haystack, size)) return (int)i;
+	}
+
+	va_end(v_haystacks);	
+	return -1;
+}

src/main.c

@@ -13,6 +13,7 @@
 #include <tests.h>
 
 #include <map.h>
+#include <comp.h>
 
 void prog_info(FILE* out)
 {
@@ -60,8 +61,16 @@ inv_args:
 	map_t needle;
 	INFO("Mapping needle file `%s'", argv[1]);
 	if(!map_handle_err(map_file(argv[1], false, 0, 0, &needle))) return PROG_RET_MAP_NEEDLE_FAILED;
+	if(!map_handle_err(map_preload(&needle, false))) WARN("Failed to advise kernel about memory access: needle");
 
+	//TODO: Map argv[2...]
+	//TODO: Setup thread-pool.
+	//TODO: Dispatch haystack maps to threadpool.
+	//TODO: Use either `cmp_find()` or `cmp_find_many()` to find the `needle` (mapped above) within those haystacks.
+	//TODO: Within the threadpool: output information regarding each match/nonmatch.
+	//TODO: Join the threadpool and consolidate results.
 
+	//TODO: Should we return an error (`PROG_RET_MAP_HAYSTACK_N_FAILED(n)`) if one (or more) of the haystacks fail? Or consolidate multiple failures into `PROG_RET_MAP_HAYSTACK_FAILED | (failures)`? The latter would be the most complete.
 
 	if(!map_handle_err(map_free(needle))) return PROG_RET_UNMAP_NEEDLE_FAILED;
 	TRACE("main end");

src/map.c

@@ -84,6 +84,15 @@ map_result_t map_free(map_t map)
 	return MAP_SUCCESS;
 }
 
+map_result_t map_preload(map_t *pINOUT map, bool random)
+{
+	TRACE("preloading map %p (%p->%lu) for immediate %s access", map, map->origin, map->len, random ? "random" : "sequential");
+	return madvise(map->origin, map->len, MADV_WILLNEED | (random ? MADV_RANDOM : MADV_SEQUENTIAL)) != 0 
+		? MAP_ERR_ADVISE
+		: MAP_SUCCESS;
+	
+}
+
 const char* map_error_str(map_result_t res)
 {
 	switch(res)
@@ -94,6 +103,7 @@ const char* map_error_str(map_result_t res)
 		CASE(MAP_ERR_OPEN, "open() failed (mapping a filepath)");
 		CASE(MAP_ERR_CLOSE, "close() failed (freeing a file-map)");
 		CASE(MAP_ERR_STAT, "fstat() failed: (mapping a full filepath)");
+		CASE(MAP_ERR_ADVISE, "madvise() failed: (preloading mapped file)");
 
 		CASE(MAP_SUCCESS, "success");
 #undef CASE