Make append buffer contiguous and update iterators

include/vase/iterators/iter.h

@@ -0,0 +1,9 @@
+#pragma once
+
+#include "../shard.h"
+#include "pch.h"
+
+enum struct Direction : uint8_t {
+  Forward,
+  Backward
+};

include/vase/iterators/line.h

@@ -1,22 +1,20 @@
 #pragma once
 
 #include "../shard.h"
-#include "chunk.h"
 #include "pch.h"
+#include "petal.h"
 
 struct LineIterator {
-  ChunkIterator it;
-  Direction dir;
-
+  PetalIterator it;
   const char *chunk;
   uint64_t len;
-  uint64_t offset = 0;
-  uint64_t chunk_offset = 0;
-  bool at_end = false;
+  Direction dir;
+  uint64_t current_offset = 0;
+  uint64_t last_line_offset = 0;
 
-  LineIterator(Shard *r, uint64_t start_line, Direction dir);
+  LineIterator(Shard *root, uint64_t line_num, Direction dir);
   ~LineIterator() = default;
 
-  bool next(std::string &line);
+  bool next(std::string *line);
   uint64_t byte_offset();
 };

include/vase/iterators/petal.h

@@ -1,30 +1,27 @@
 #pragma once
 
 #include "../shard.h"
+#include "iter.h"
 #include "pch.h"
 
-enum struct Direction : uint8_t {
-  Forward,
-  Backward
-};
-
-struct ChunkIterator {
+struct PetalIterator {
   Direction dir;
   Shard *root = nullptr;
   std::vector<Shard *> stack;
   Petal *petal = nullptr;
-  uint64_t petal_offset = 0;
   uint64_t global_offset = 0;
+  uint64_t last_offset = 0;
+  uint64_t petal_offset = 0;
   uint64_t global_line = 0;
-  bool at_end = false;
 
-  ChunkIterator(Shard *r, Direction dir);
-
-  ~ChunkIterator();
+  PetalIterator(Shard *r, Direction dir);
+  ~PetalIterator() = default;
 
   void seek_offset(uint64_t offset);
   void seek_line(uint64_t offset);
   bool next(const char **data, uint64_t *out_len);
   uint64_t byte_offset();
-  uint64_t line_offset();
+
+private:
+  Petal *_next(uint64_t *offset);
 };