1 files changed, 160 insertions, 0 deletions

diff --git a/src/storage.c b/src/storage.c
new file mode 100644
index 0000000..f934c4f
--- /dev/null
+++ b/src/storage.c
@@ -0,0 +1,160 @@
+#include "db.h"
+
+
+row *newRow(const char path[MAXPATH]){
+	row *nr = malloc(sizeof(row));
+	memcpy(nr->path, path, MAXPATH);
+	memcpy(nr->tags, "\0", MAXTAGS);
+	nr->numTags = 0;
+	nr->lenTags = 0;
+
+	return nr;
+}
+
+// Splits src into words based on a separator character (sep) and stores them in arr,
+// and the length in len. Inspired by https://github.com/joshdk/tag/blob/master/src/dsv.c's split
+static void split(const char *src, char sep, char ***arr, int *len){
+	int slen = 0, ai = 0, wnum = 0, wlen = 0;
+
+	while(src[slen] != '\0'){
+		if(src[slen] == sep){
+			++wnum;
+		}
+		++slen;
+	}
+	if(slen != 0 && src[slen-1] != sep){
+		++wnum;
+	}
+	++slen;
+
+	*arr = calloc((wnum+1), sizeof(char*));
+	for(int i = 0; i < slen; ++i){
+		if(src[i] == sep || src[i] == '\0'){
+			(*arr)[ai] = calloc(wlen+1, sizeof(char));
+			for(int j = i-wlen, k = 0; j < i; ++j, ++k){
+				(*arr)[ai][k] = src[j];
+			}
+			++ai;
+			wlen = 0;
+		}else{
+			++wlen;
+		}
+	}
+	*len = wnum;
+}
+
+static void swapWords(char ***arr, int a, int b){
+	char *tmp = (*arr)[a];
+	(*arr)[a] = (*arr)[b];
+	(*arr)[b] = tmp;
+}
+
+static char *normalizeTag(char *tag){
+	uint16_t l = len(tag);
+	char *ntag = calloc(l+1, sizeof(char));
+	for(int i = 0; i < l; ++i){
+		ntag[i] = tolower(tag[i]);
+	}
+	return ntag;
+}
+
+// Adds a tag in the tags array in the row r, sorted by natural string
+// comparison with strnatcmp. We assume that when adding a tag all other
+// tags are already sorted. Nothing is done if the tag is already in the tags
+void insertTag(row *r, char *tag){
+	int l, ltag = len(tag);
+	if(ltag == 0){
+		return;
+	}
+
+	tag = normalizeTag(tag);
+
+	// Dump tags into array of strings and add tag
+	char **arr, **tmp;
+	split(r->tags, ';', &arr, &l);
+	
+	if((tmp = realloc(arr, (l+1)*sizeof(char*))) != NULL){
+		arr = tmp;
+		tmp = NULL;
+	}else{
+		fprintf(stderr, "Error reallocating array (insertTag)");
+		exit(EXIT_FAILURE);
+	}
+	arr[l] = malloc((len(tag)+1)*sizeof(char));
+	strcpy(arr[l], tag);
+	
+	// Sort tag by natural string comparison, starting from the last element (the new tag)
+	for(int i = l; i > 0; --i){
+		switch(strnatcmp(arr[i-1], arr[i])){
+			case 1:
+				// arr[i-1] is higher than arr[i]; swap them
+				swapWords(&arr, i, i-1);
+				break;
+			case -1:
+				// arr[i-1] is lower than arr[i]; exit loop
+				i = 0;
+				break;
+			case 0:
+				// The tag already exists, no need to alter anything
+				free(arr);
+				return;
+		}
+	}
+	++l; // Succesfully added new tag
+
+	// Insert tags back into tags member of row structure with the ';' separator in between them
+	int tagnum = 0;
+	for(int i = 0; i < l; ++i){
+		int j = 0;
+		while(arr[i][j] != '\0'){
+			r->tags[tagnum] = arr[i][j];
+			++j;
+			++tagnum;
+		}
+		r->tags[tagnum++] = ';';
+	}
+	r->tags[tagnum] = '\0';
+	r->numTags = l;
+	r->lenTags = tagnum;
+}
+
+// Remove a tag from the tags array in the row r
+// Nothing is done if the tag isnt in the tags
+void removeTag(row *r, char *tag){
+	int l, ltag = len(tag);
+	if(ltag == 0){
+		return;
+	}
+
+	tag = normalizeTag(tag);
+
+	// Dump tags into array of strings
+	char **arr;
+	split(r->tags, ';', &arr, &l);
+
+	// Search for tag and remove it
+	for(int i = 0; i <= l; ++i){
+		if(sameStr(arr[i], tag)){
+			for(int j = i; j < l; ++j){
+				arr[j] = arr[j+1];
+			}
+			--l;
+			break;
+		}
+	}
+
+	// Insert tags back into tags member of row structure with the ';' separator in between them
+	int tagnum = 0;
+	for(int i = 0; i < l; ++i){
+		int j = 0;
+		while(arr[i][j] != '\0'){
+			r->tags[tagnum] = arr[i][j];
+			++j;
+			++tagnum;
+		}
+		r->tags[tagnum++] = ';';
+	}
+	r->tags[tagnum] = '\0';
+	r->numTags = l;
+	r->lenTags = tagnum;
+}
\ No newline at end of file