X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=visor;a=blobdiff_plain;f=libvisor%2Fsrc%2Fvisor.c;h=cefc924618d2445571873b100d0362c2d38377bf;hp=b4ef116dcc4cf636314131c2798341fbbc95ab58;hb=a4536cf08230dba14f221b661abd7804fcc1ebbc;hpb=a3d913263bd55389a60c8db96d1ea1fc11acf178

diff --git a/libvisor/src/visor.c b/libvisor/src/visor.c
index b4ef116..cefc924 100644
--- a/libvisor/src/visor.c
+++ b/libvisor/src/visor.c
@@ -179,12 +179,30 @@ struct vi_buffer *vi_prev_buf(struct visor *vi)
 	return vi->buflist ? vi->buflist->prev : 0;
 }
 
-static int add_span(struct vi_buffer *vb, int src, vi_addr start, unsigned long size)
+/* split_span splits the span sp. if size > 0 it moves the second part to sp+2,
+ * leaving an empty place at sp+1 for the new span. The start point of the
+ * second part is adjusted by size.
+ *
+ * It can't fail, because it's always called with the span array having at
+ * least two empty slots (see: add_span).
+ */
+void split_span(struct vi_buffer *vb, struct vi_span *sp, vi_addr at, unsigned long size)
+{
+	struct vi_span *tail = sp + (size ? 2 : 1);
+	int num_move = vb->spans + vb->num_spans - sp - 1;
+
+	memmove(tail + 1, sp + 1, num_move);
+	vb->num_spans += tail - sp;
+
+}
+
+static int add_span(struct vi_buffer *vb, vi_addr at, int src, vi_addr start, unsigned long size)
 {
 	struct visor *vi = vb->vi;
 	struct vi_span *sp;
 
-	if(vb->num_spans >= vb->max_spans) {
+	/* make sure we have space for at least two new spans (split + add) */
+	if(vb->num_spans + 1 >= vb->max_spans) {
 		int newmax = vb->max_spans > 0 ? (vb->max_spans << 1) : 16;
 		struct vi_span *tmp = vi_realloc(vb->spans, newmax * sizeof *tmp);
 		if(!tmp) return -1;
@@ -192,9 +210,16 @@ static int add_span(struct vi_buffer *vb, int src, vi_addr start, unsigned long
 		vb->max_spans = newmax;
 	}
 
-	sp = vb->spans + vb->num_spans++;
-	sp->beg = start;
+	if((sp = vi_buf_find_span(vb, at))) {
+		split_span(vb, sp++, at, size);
+	} else {
+		sp = vb->spans + vb->num_spans;
+	}
+
+	sp->src = src;
+	sp->start = start;
 	sp->size = size;
+	vb->num_spans++;
 	return 0;
 }
 
@@ -229,7 +254,7 @@ int vi_buf_read(struct vi_buffer *vb, const char *path)
 
 	vi_buf_reset(vb);
 
-	if(!(fp = vi_open(path))) {
+	if(!(fp = vi_open(path, VI_RDONLY | VI_CREAT))) {
 		return -1;
 	}
 	plen = strlen(path);
@@ -253,7 +278,7 @@ int vi_buf_read(struct vi_buffer *vb, const char *path)
 			vb->file_mapped = 1;
 		}
 
-		if(add_span(vb, SPAN_ORIG, 0, fsz) == -1) {
+		if(add_span(vb, 0, SPAN_ORIG, 0, fsz) == -1) {
 			vi_error(vi, "failed to allocate span\n");
 			vi_buf_reset(vb);
 			return -1;
@@ -262,3 +287,79 @@ int vi_buf_read(struct vi_buffer *vb, const char *path)
 	vb->orig_size = fsz;
 	return 0;
 }
+
+int vi_buf_write(struct vi_buffer *vb, const char *path)
+{
+	int i, wbuf_count;
+	struct visor *vi = vb->vi;
+	vi_file *fp;
+	static char wbuf[512];
+
+	if(!path) path = vb->path;
+	if(!path) {
+		vi_error(vi, "failed to write buffer, unknown path\n");
+		return -1;
+	}
+
+	if(!(fp = vi_open(path, VI_WRONLY | VI_CREAT))) {
+		vi_error(vi, "failed to open %s for writing\n", path);
+		return -1;
+	}
+
+	wbuf_count = 0;
+	for(i=0; i<vb->num_spans; i++) {
+		struct vi_span *sp = vb->spans + i;
+		const char *sptxt = vi_buf_span_text(vb, sp);
+		int n, count = 0;
+		while(count < sp->size) {
+			n = sp->size - count;
+			if(n > sizeof wbuf - wbuf_count) {
+				n = sizeof wbuf - wbuf_count;
+			}
+			memcpy(wbuf + wbuf_count, sptxt + count, n);
+			count += n;
+			wbuf_count += n;
+		}
+
+		if(wbuf_count >= sizeof wbuf) {
+			vi_write(fp, wbuf, wbuf_count);
+		}
+	}
+
+	if(wbuf_count > 0) {
+		vi_write(fp, wbuf, wbuf_count);
+	}
+	vi_close(fp);
+	return 0;
+}
+
+long vi_buf_size(struct vi_buffer *vb)
+{
+	int i;
+	long sz = 0;
+
+	for(i=0; i<vb->num_spans; i++) {
+		sz += vb->spans[i].size;
+	}
+	return sz;
+}
+
+struct vi_span *vi_buf_find_span(struct vi_buffer *vb, vi_addr at)
+{
+	int i;
+	long sz = 0;
+
+	for(i=0; i<vb->num_spans; i++) {
+		sz += vb->spans[i].size;
+		if(sz > at) {
+			return vb->spans + i;
+		}
+	}
+	return 0;
+}
+
+const char *vi_buf_span_text(struct vi_buffer *vb, struct vi_span *sp)
+{
+	const char *buf = sp->src == SPAN_ORIG ? vb->orig : vb->add;
+	return buf + sp->start;
+}