Use dynamic stack and ignore repo in traverse().

1 files changed, 32 insertions, 16 deletions

diff --git a/main.c b/main.c
index f709768..97083ba 100644
--- a/main.c
+++ b/main.c
@@ -13,13 +13,11 @@
 #define REPO   ".cvn"
 #define INDEX  "index"
 
-#define MAX_SUBDIRS  256
-
 static inline void init(int argc, char *argv[]);
 static inline void status(int argc, char *argv[]);
 
-/* helpers */
 static inline void traverse(void);
+static inline uint8_t ignore(const char *path);
 
 struct command {
 	char *name;
@@ -99,20 +97,34 @@ static inline void status(int argc, char *argv[])
 	traverse();
 }
 
+static inline uint8_t ignore(const char *path)
+{
+	return strcmp(path, ".") == 0 || 
+	       strcmp(path, "..") == 0 || 
+	       strcmp(path, REPO) == 0;
+}
+
 static inline void traverse(void)
 {
 	DIR *dir;
 	char *path, *rel_path;
 	struct stat st;
 	struct dirent *entry;
-	int subdirs_len;
-	char *subdirs[MAX_SUBDIRS];
-	
-	subdirs_len = 0;
-	subdirs[subdirs_len++] = strdup(".");
-
-	while (subdirs_len) {
-		path = subdirs[--subdirs_len];
+	int i, subdirs_len;
+	char **subdirs;
+
+	i = 0;
+	// On 64-bit systems: 512 * 8 (ptr size) = 4096 - typical page size / 64 cache lines
+	// Page-aligned buffers that fit in CPU cache lines reduce mmu overhead (play well
+	// with the CPU's TLB (Tranlation Lookaside Buffer).
+	subdirs_len = 512;
+	subdirs = malloc(sizeof(subdirs[0]) * subdirs_len);
+	if (!subdirs)
+		err(1, "malloc() failed");
+	subdirs[i++] = strdup(".");
+
+	while (i > 0) {
+		path = subdirs[--i];
 		if (!(dir = opendir(path))) {
 			warn("Failed to open directory %s", path);
 			free(path);
@@ -120,7 +132,7 @@ static inline void traverse(void)
 		}
 
 		while ((entry = readdir(dir)) != NULL) {
-			if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
+			if (ignore(entry->d_name))
 				continue;
 			if (asprintf(&rel_path, "%s/%s", path, entry->d_name) == -1)
 				err(1, "asprintf() failed");
@@ -130,16 +142,20 @@ static inline void traverse(void)
 				continue;
 			}
 			if (S_ISDIR(st.st_mode)) {
-				if (subdirs_len >= MAX_SUBDIRS)
-					errx(1, "Repository too large: directory tree too deep/wide");
-				subdirs[subdirs_len++] = rel_path;
+				if (i >= subdirs_len) {
+					subdirs_len <<= 1;
+					subdirs = realloc(subdirs, sizeof(subdirs[0]) * subdirs_len);
+					if (!subdirs)
+						err(1, "realloc() failed");
+				}
+				subdirs[i++] = rel_path;
 			} else {
 				printf("File: %s\n", rel_path);
 				free(rel_path);
 			}
 		}
-
 		free(path);
 		closedir(dir);
 	}
+	free(subdirs);
 }