From 1866963738cbefa801d91b73ab140388e50da4a7 Mon Sep 17 00:00:00 2001
From: Laria Carolin Chabowski <laria@laria.me>
Date: Sat, 22 Jul 2023 22:30:07 +0200
Subject: [PATCH] gc: Add blockstats

---
 src/builtins.c |  5 ++++-
 src/gc.c       | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/gc.h       |  1 +
 3 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/src/builtins.c b/src/builtins.c
index f48a559..cbcbc9a 100644
--- a/src/builtins.c
+++ b/src/builtins.c
@@ -405,6 +405,9 @@ impl_gc(apfl_ctx ctx)
         TRY_FORMAT(ctx, apfl_gc_debug_dump_graph(&ctx->gc, w));
     } else if (apfl_string_eq(sv, "collect")) {
         apfl_gc_full(&ctx->gc);
+    } else if (apfl_string_eq(sv, "blockstats")) {
+        struct apfl_io_writer w = apfl_get_output_writer(ctx);
+        TRY_FORMAT(ctx, apfl_gc_debug_blockstats(&ctx->gc, w));
     } else {
         apfl_raise_const_error(ctx, "Unknown gc command");
     }
@@ -484,7 +487,7 @@ impl_fopen(apfl_ctx ctx)
     if (argc > 1) {
         apfl_get_list_member_by_index(ctx, 0, 1);
     } else {
-        apfl_push_const_string(ctx, "rb");
+        apfl_push_const_string(ctx," rb");
     }
     const char *mode = getcstring(ctx, -1);
 
diff --git a/src/gc.c b/src/gc.c
index 1213978..46f88f5 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -650,6 +650,56 @@ apfl_gc_debug_dump_graph(struct gc *gc, struct apfl_io_writer w)
     return true;
 }
 
+typedef size_t statuscounts[4];
+
+static bool
+blockstat_line(struct apfl_io_writer w, size_t i, statuscounts counts)
+{
+    FMT_TRY(apfl_format_put_int(w, (int)i));
+    FMT_TRY(apfl_io_write_byte(w, '\t'));
+    FMT_TRY(apfl_format_put_int(w, (int)counts[GC_STATUS_FREE]));
+    FMT_TRY(apfl_io_write_byte(w, '\t'));
+    FMT_TRY(apfl_format_put_int(w, (int)counts[GC_STATUS_BLACK]));
+    FMT_TRY(apfl_io_write_byte(w, '\t'));
+    FMT_TRY(apfl_format_put_int(w, (int)counts[GC_STATUS_GREY]));
+    FMT_TRY(apfl_io_write_byte(w, '\t'));
+    FMT_TRY(apfl_format_put_int(w, (int)counts[GC_STATUS_WHITE]));
+    FMT_TRY(apfl_io_write_byte(w, '\n'));
+
+    return true;
+}
+
+bool
+apfl_gc_debug_blockstats(struct gc *gc, struct apfl_io_writer w)
+{
+    statuscounts total = {0, 0, 0, 0};
+    size_t i = 0;
+
+    FMT_TRY(apfl_io_write_string(w, "block#\tfree\tblack\tgrey\twhite\n========================================\n"));
+
+    for (
+        struct gc_block *cur = gc->block;
+        cur != NULL;
+        cur = cur->next
+    ) {
+        statuscounts block = {0, 0, 0, 0};
+
+        for (size_t j = 0; j < GC_OBJECTS_PER_BLOCK; j++) {
+            enum gc_status status = cur->objects[j].status;
+            block[status]++;
+            total[status]++;
+        }
+
+        FMT_TRY(blockstat_line(w, i, block));
+        i++;
+    }
+
+    FMT_TRY(apfl_io_write_string(w, "========================================\n"));
+    FMT_TRY(blockstat_line(w, i, total));
+
+    return true;
+}
+
 void
 apfl_gc_deinit(struct gc *gc)
 {
diff --git a/src/gc.h b/src/gc.h
index 5beb2ac..ec8b350 100644
--- a/src/gc.h
+++ b/src/gc.h
@@ -73,6 +73,7 @@ void apfl_gc_init(struct gc *, struct apfl_allocator, gc_roots_getter, void *roo
 void apfl_gc_deinit(struct gc *);
 
 bool apfl_gc_debug_dump_graph(struct gc *, struct apfl_io_writer);
+bool apfl_gc_debug_blockstats(struct gc *, struct apfl_io_writer);
 
 size_t apfl_gc_tmproots_begin(struct gc *gc);
 void apfl_gc_tmproots_restore(struct gc *gc, size_t);