split and span mess

diff --git a/libvisor/include/visor.h b/libvisor/include/visor.h
index 55dcc48..73fb7dc 100644 (file)
--- a/libvisor/include/visor.h
+++ b/libvisor/include/visor.h
@@ -26,8 +26,9 @@ struct visor;
 struct vi_buffer;
 
 struct vi_span {
-       vi_addr beg;
+       vi_addr start;
        unsigned long size;
+       int src;
 };
 
 enum vi_motdir {
@@ -135,6 +136,9 @@ int vi_buf_read(struct vi_buffer *vb, const char *path);
 int vi_buf_write(struct vi_buffer *vb, const char *path);
 long vi_buf_size(struct vi_buffer *vb);
 
+/* find the span which corresponds to the specified text position */
+struct vi_span *vi_buf_find_span(struct vi_buffer *vb, vi_addr at);
+
 void vi_buf_ins_begin(struct vi_buffer *vb, vi_motion mot);
 void vi_buf_insert(struct vi_buffer *vb, char *s);
 void vi_buf_ins_end(struct vi_buffer *vb);

diff --git a/libvisor/src/vilibc.h b/libvisor/src/vilibc.h
index 047fa18..f9e8d06 100644 (file)
--- a/libvisor/src/vilibc.h
+++ b/libvisor/src/vilibc.h
@@ -30,6 +30,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #include <stdarg.h>
 #include <ctype.h>
 #include <limit.h>
+#include <assert.h>
 #else
 
 int atoi(const char *str);
@@ -71,6 +72,8 @@ int isspace(int c);
 int toupper(int c);
 int tolower(int c);
 
+#define assert(x)
+
 #endif /* !HAVE_LIBC */
 
 struct visor;

diff --git a/libvisor/src/visor.c b/libvisor/src/visor.c
index b4ef116..08c88a7 100644 (file)
--- a/libvisor/src/visor.c
+++ b/libvisor/src/visor.c
@@ -179,12 +179,32 @@ 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->num_spans - sp - 1;
+
+       memmove(tail + 1, sp + 1, num_move);
+       vb->num_span += tail - sp;
+
+       sp->size ... CONTINUE HERE.
+}
+
+static int add_span(struct vi_buffer *vb, vi_addr at, int src, vi_addr start, unsigned long size)
+{
+       int i;
        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 +212,16 @@ 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->addr = start;
        sp->size = size;
+       vb->num_spans++;
        return 0;
 }
 
@@ -262,3 +289,7 @@ 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)
+{
+}