Rearrange project files.

include/internal/vase/shard.h

@@ -0,0 +1,113 @@
+#pragma once
+
+#include "buffer/buffer.h"
+#include "buffer/original.h"
+#include "constants.h"
+#include "pch.h"
+
+struct Shard {
+  enum struct Kind : uint8_t {
+    Branch,
+    Petal
+  } kind;
+
+  uint8_t height;
+
+  uint64_t length;
+  uint64_t lines;
+
+  std::atomic_uint64_t refs;
+
+  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);
+  static void release(Shard *n);
+
+  static Shard *from_file(std::filesystem::path path, OriginalBuffer *b);
+  static std::vector<Shard *> from_swap(std::filesystem::path path, 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(Shard *root, Shard *leaf);
+  static Shard *build(Shard **pieces, uint64_t lo, uint64_t hi);
+};
+
+struct Branch : Shard {
+  Shard *left;
+  Shard *right;
+
+  Branch(Shard *l, Shard *r)
+      : Shard(
+          Kind::Branch,
+          l->length + r->length,
+          l->lines + r->lines,
+          1 + std::max(l->height, r->height)
+        ),
+        left(l), right(r) {
+    retain(left);
+    retain(right);
+  };
+};
+
+struct Petal : Shard {
+  Buffer *source;
+  uint64_t pos;
+
+  Petal(uint64_t length, uint64_t lines, Buffer *source, uint64_t pos)
+      : 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";
+}