1 files changed, 60 insertions, 0 deletions
diff --git a/src/hist_view.h b/src/hist_view.h
new file mode 100644
index 0000000..0214c0b
--- /dev/null
+++ b/src/hist_view.h
@@ -0,0 +1,60 @@
+#ifndef TERM_HIST_VIEW_H
+#define TERM_HIST_VIEW_H
+
+#include "hist.h"
+
+struct line_pos {
+    uint64_t id;
+    uint32_t seg;
+};
+
+struct view_anchor {
+    uint64_t line_id;
+    uint64_t cell;
+    uint64_t base_cell;
+    uint32_t seg;
+    bool active;
+};
+
+struct hist_view {
+    struct view_anchor anchor;
+
+    /* Line ids map to circular slots. Tree sums use physical slot order. */
+    uint64_t *fenwick;
+    uint32_t *counts;
+    uint64_t total_rows;
+    uint64_t first_id, end_id;
+    uint64_t epoch, head, tail, last_cells;
+    int cols;
+    uint32_t cap;
+    int index_cols;
+};
+
+void term_hist_view_init(struct hist_view *v);
+void term_hist_view_free(struct hist_view *v);
+void term_hist_view_clear(struct hist_view *v);
+
+/* Update the index during snapshot capture. Reads do not change it. */
+bool term_hist_view_sync(struct hist_view *v, const struct hist *h, int cols);
+void term_hist_view_refine(struct hist_view *v, struct hist *h, int cols, int rows);
+uint64_t term_hist_view_rows(const struct hist_view *v, const struct hist *h, int cols);
+bool term_hist_view_find_row(const struct hist_view *v, const struct hist *h, int row,
+                        int cols, uint64_t *id, int *seg);
+
+/* Read the offset from the anchor at the current width. */
+int term_hist_view_scroll_offset(const struct hist_view *v, const struct hist *h, int cols);
+void term_hist_view_scroll(struct hist_view *v, const struct hist *h, int cols,
+                      struct line_pos screen_top, int lines);
+void term_hist_view_scroll_to(struct hist_view *v, const struct hist *h, int cols,
+                         struct line_pos screen_top, int offset);
+void term_hist_view_reset_bottom(struct hist_view *v);
+
+/* Clamp an evicted anchor. This does not update the index on the write path. */
+void term_hist_view_note_push(struct hist_view *v, const struct hist *h, int cols);
+void term_hist_view_rewrap(struct hist_view *v, const struct hist *h, int cols);
+
+bool term_hist_view_row_pos(const struct hist_view *v, const struct hist *h, int cols,
+                       int screen_rows, struct line_pos screen_top, int y,
+                       uint64_t *out_id, int *out_seg, int *out_screen_y);
+
+#endif