Make append buffer contiguous and update iterators

include/vase/shard.h

@@ -7,7 +7,7 @@
 #include "utils/utils.h"
 
 struct Shard {
-  enum struct ShardKind : uint8_t {
+  enum struct Kind : uint8_t {
     Branch,
     Petal
   } kind;
@@ -19,7 +19,7 @@ struct Shard {
 
   std::atomic_uint64_t refs;
 
-  Shard(ShardKind kind, uint64_t length, uint64_t lines, uint8_t height)
+  Shard(Kind kind, uint64_t length, uint64_t lines, uint8_t height)
       : kind(kind), height(height), length(length), lines(lines), refs(1) {};
 
   static void retain(Shard *n);
@@ -27,14 +27,13 @@ struct Shard {
 
   static Shard *from_file(std::filesystem::path path, OriginalBuffer *b);
   static std::vector<Shard *> from_swap(std::filesystem::path path, OriginalBuffer *b);
-  static Shard *new_empty(OriginalBuffer *b);
 
   static std::pair<Shard *, Shard *> split(Shard *n, uint64_t offset);
   static Shard *concat(Shard *left, Shard *right);
   static Shard *merge(Shard *a, Shard *b);
   static Shard *merge_leaves(Shard *a, Shard *b);
-  static Shard *append_leaf(Shard *root, Shard *leaf);
-  static Shard *build_balanced(Shard **pieces, uint64_t lo, uint64_t hi);
+  static Shard *append(Shard *root, Shard *leaf);
+  static Shard *build(Shard **pieces, uint64_t lo, uint64_t hi);
 };
 
 struct Branch : Shard {
@@ -43,7 +42,7 @@ struct Branch : Shard {
 
   Branch(Shard *l, Shard *r)
       : Shard(
-          ShardKind::Branch,
+          Kind::Branch,
           l->length + r->length,
           l->lines + r->lines,
           1 + std::max(l->height, r->height)
@@ -56,10 +55,60 @@ struct Branch : Shard {
 
 struct Petal : Shard {
   Buffer *source;
-
   uint64_t pos;
 
   Petal(uint64_t length, uint64_t lines, Buffer *source, uint64_t pos)
-      : Shard(ShardKind::Petal, length, lines, 1),
+      : Shard(Kind::Petal, length, lines, 1),
         source(source), pos(pos) {};
 };
+
+extern inline void dump_shard(Shard *node, int depth = 0) {
+  if (!node) {
+    std::cout << std::string(depth * 2, ' ') << "<null>\n";
+    return;
+  }
+
+  std::string indent(depth * 2, ' ');
+
+  std::cout << indent
+            << "Shard@" << node
+            << " kind=";
+
+  switch (node->kind) {
+  case Shard::Kind::Branch:
+    std::cout << "Branch";
+    break;
+  case Shard::Kind::Petal:
+    std::cout << "Petal";
+    break;
+  }
+
+  std::cout
+    << " height=" << unsigned(node->height)
+    << " length=" << node->length
+    << " lines=" << node->lines
+    << " refs=" << node->refs.load()
+    << "\n";
+
+  if (node->kind == Shard::Kind::Branch) {
+    auto *branch = static_cast<Branch *>(node);
+
+    std::cout << indent << "  left:\n";
+    dump_shard(branch->left, depth + 2);
+
+    std::cout << indent << "  right:\n";
+    dump_shard(branch->right, depth + 2);
+  } else {
+    auto *petal = static_cast<Petal *>(node);
+
+    std::cout
+      << indent << "  source=" << petal->source
+      << " pos=" << petal->pos
+      << " length=" << petal->length
+      << " lines=" << petal->lines
+      << "\n";
+  }
+
+  if (!depth)
+    std::cout << "\n\n";
+}