Perfect

- Make original buffer use a disk backed mapping to save memory.
- rearrange api function headers for search etc.
- fix bugs with iterators.
- support uint64_t for all byte and line offsets to allow for much larger files to be opened.
- and more minor bug fixes.

include/pch.h

@@ -40,9 +40,12 @@ extern "C" {
 #include <shared_mutex>
 #include <signal.h>
 #include <stack>
+#include <stdexcept>
 #include <string.h>
 #include <string>
 #include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <termios.h>

include/vase/buffer/append.h

@@ -8,16 +8,16 @@ struct AppendBuffer : Buffer {
   using TChunk = char[APPEND_CHUNK_SIZE];
   std::vector<TChunk *> buf;
   TChunk *t_current;
-  uint32_t current_offset{0};
+  uint64_t current_offset{0};
-  uint32_t t_offset{0};
+  uint64_t t_offset{0};
 
   AppendBuffer();
 
   ~AppendBuffer();
 
-  uint32_t key(char c);
+  uint64_t append(char c);
-  uint32_t append(const char *text, uint32_t length);
+  uint64_t append(const char *text, uint64_t length);
 
-  const char *read(uint32_t pos, uint32_t *out_len);
+  const char *read(uint64_t pos, uint64_t *out_len);
-  inline uint32_t length();
+  inline uint64_t length();
 };

include/vase/buffer/buffer.h

@@ -3,7 +3,7 @@
 #include "pch.h"
 
 struct Buffer {
-  virtual const char *read(uint32_t pos, uint32_t *out_len) = 0;
+  virtual const char *read(uint64_t pos, uint64_t *out_len) = 0;
-  virtual inline uint32_t length() = 0;
+  virtual inline uint64_t length() = 0;
   virtual ~Buffer() = default;
 };

include/vase/buffer/original.h

@@ -4,14 +4,14 @@
 #include "pch.h"
 
 struct OriginalBuffer : Buffer {
-  char *buf;
+  const char *buf;
-  uint32_t len;
+  uint64_t len;
-
+  int fd = -1;
-  // Add 2 modes here, normal and lazy, lazy copies the file to a safe location and uses mmap.
-  OriginalBuffer(std::string path);
 
+  OriginalBuffer();
   ~OriginalBuffer();
 
-  const char *read(uint32_t pos, uint32_t *out_len);
+  void initialize();
-  uint32_t length();
+  const char *read(uint64_t pos, uint64_t *out_len);
+  uint64_t length();
 };

include/vase/constants.h

@@ -2,8 +2,8 @@
 
 #include "pch.h"
 
-constexpr uint32_t APPEND_CHUNK_SIZE = 64 * 1024;
+constexpr uint64_t APPEND_CHUNK_SIZE = 64 * 1024;
-constexpr uint32_t PETAL_SIZE_MAX = 32 * 1024;
+constexpr uint64_t PETAL_SIZE_MAX = 32 * 1024;
 
 static_assert(
   APPEND_CHUNK_SIZE > PETAL_SIZE_MAX,

include/vase/iterators/chunk.h

@@ -13,15 +13,18 @@ struct ChunkIterator {
   Shard *root = nullptr;
   std::vector<Shard *> stack;
   Petal *petal = nullptr;
-  uint32_t petal_offset = 0;
+  uint64_t petal_offset = 0;
-  uint32_t global_offset = 0;
+  uint64_t global_offset = 0;
+  uint64_t global_line = 0;
+  bool at_end = false;
 
   ChunkIterator(Shard *r, Direction dir);
 
   ~ChunkIterator();
 
-  void seek_offset(uint32_t offset);
+  void seek_offset(uint64_t offset);
-  void seek_line(uint32_t offset);
+  void seek_line(uint64_t offset);
-  bool next(const char **data, uint32_t *out_len);
+  bool next(const char **data, uint64_t *out_len);
-  uint32_t byte_offset();
+  uint64_t byte_offset();
+  uint64_t line_offset();
 };

include/vase/iterators/line.h

@@ -9,11 +9,14 @@ struct LineIterator {
   Direction dir;
 
   const char *chunk;
-  uint32_t len;
+  uint64_t len;
+  uint64_t offset = 0;
+  uint64_t chunk_offset = 0;
+  bool at_end = false;
 
-  LineIterator(Shard *r, uint32_t start_line, Direction dir);
+  LineIterator(Shard *r, uint64_t start_line, Direction dir);
   ~LineIterator() = default;
 
   bool next(std::string &line);
-  uint32_t byte_offset();
+  uint64_t byte_offset();
 };

include/vase/search.h

@@ -1,21 +0,0 @@
-#pragma once
-
-#include "pch.h"
-#include "vase/shard.h"
-
-struct RegexGroup {
-  uint32_t start{UINT32_MAX};
-  uint32_t end{UINT32_MAX};
-};
-
-struct RegexMatch {
-  uint32_t start;
-  uint32_t end;
-  RegexGroup groups[9]{};
-};
-
-std::vector<RegexMatch> regex_search(
-  Shard *root, std::string_view pattern_str,
-  uint32_t start_offset, uint32_t end_offset,
-  std::string_view options
-);

include/vase/shard.h

@@ -14,12 +14,12 @@ struct Shard {
 
   uint8_t height;
 
-  uint32_t length;
+  uint64_t length;
-  uint32_t lines;
+  uint64_t lines;
 
-  std::atomic_uint32_t refs;
+  std::atomic_uint64_t refs;
 
-  Shard(ShardKind kind, uint32_t length, uint32_t lines, uint8_t height)
+  Shard(ShardKind 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);
@@ -46,18 +46,19 @@ struct Branch : Shard {
 struct Petal : Shard {
   Buffer *source;
 
-  uint32_t pos;
+  uint64_t pos;
 
-  Petal(uint32_t length, uint32_t lines, Buffer *source, uint32_t pos)
+  Petal(uint64_t length, uint64_t lines, Buffer *source, uint64_t pos)
       : Shard(ShardKind::Petal, length, lines, 1),
         source(source), pos(pos) {};
 };
 
-Shard *create_shards(Buffer *o);
+Shard *create_file_shards(std::string &path, OriginalBuffer *b);
+Shard *create_swap_shards(std::string &path, OriginalBuffer *b);
 
-std::pair<Shard *, Shard *> split_shard(Shard *n, uint32_t offset);
+std::pair<Shard *, Shard *> split_shard(Shard *n, uint64_t offset);
 Shard *concat_shard(Shard *left, Shard *right);
 Shard *merge(Shard *a, Shard *b);
 Shard *merge_leaves(Shard *a, Shard *b);
 Shard *append_leaf(Shard *root, Shard *leaf);
-Shard *build_balanced(Shard **pieces, uint32_t lo, uint32_t hi);
+Shard *build_balanced(Shard **pieces, uint64_t lo, uint64_t hi);

include/vase/vase.h

@@ -10,8 +10,8 @@
 #include "utils/utils.h"
 
 struct Point {
-  uint32_t row;
+  uint64_t row;
-  uint32_t col;
+  uint64_t col;
 };
 
 struct Range {
@@ -19,30 +19,52 @@ struct Range {
   Point end;
 };
 
+struct RegexGroup {
+  uint64_t start{UINT32_MAX};
+  uint64_t end{UINT32_MAX};
+};
+
+struct RegexMatch {
+  uint64_t start;
+  uint64_t end;
+  RegexGroup groups[9]{};
+};
+
+struct ReplacePart {
+  enum struct PartType {
+    FullMatch,
+    CaptureGroup,
+    Constant
+  } type;
+
+  std::variant<uint8_t, Shard *> value;
+};
+
 struct Vase {
-  OriginalBuffer original;
+  OriginalBuffer *original;
-  AppendBuffer append;
+  AppendBuffer *append;
   Shard *root;
 
   Vase(std::string path);
 
   ~Vase();
 
-  uint32_t length();
+  uint64_t length();
   std::string to_string();
+  std::string to_string(Range range);
 
-  Point resolve_column(uint32_t line, uint32_t column);
+  Point resolve_column(uint64_t line, uint64_t column);
 
-  LineIterator iterate(uint32_t line);
+  LineIterator iterate(uint64_t line);
 
   void insert(Point *point, char key);
-  void insert(Point *point, const char *data, uint32_t len);
+  void insert(Point *point, const char *data, uint64_t len);
-  void erase(Point *point, int64_t amount);
+  void erase(Point *point, uint64_t amount, Direction dir);
   void erase(Range range);
-  void replace(Range range, const char *data, uint32_t len);
+  void replace(Range range, const char *data, uint64_t len);
 
-  void move_clusters(Point *point, int64_t amount);
+  void move_clusters(Point *point, uint64_t amount, Direction dir);
-  void move_lines(Point *point, int64_t amount);
+  void move_lines(Point *point, uint64_t amount, Direction dir);
   void clamp(Point *point);
 
   void regex_search_replace(
@@ -50,17 +72,30 @@ struct Vase {
     std::string_view replace, std::string_view options
   );
 
+  std::vector<Range> regex_search(
+    std::string_view pattern, Range range, std::string_view options
+  );
+
   bool undo();
   bool redo();
 
   void snapshot();
-  void prune_history(uint32_t n);
+  void prune_history(uint64_t n);
+
+  bool save(std::string path);
+  bool save_swap(std::string path);
+
+  uint64_t offset_of(Point point);
+  Point point_of(uint64_t offset);
 
 private:
   std::vector<Shard *> history;
-  uint32_t history_top;
+  uint64_t history_top;
 
-  uint32_t offset_of(Point point);
+  void _insert(Point *point, const char *data, uint64_t len);
-  static void flatten(Shard *s, std::string &out);
+
-  void _insert(Point *point, const char *data, uint32_t len);
+  std::vector<ReplacePart> parse_replace(std::string_view s);
+  std::vector<RegexMatch> _regex_search(
+    std::string_view pattern, Range range, std::string_view options
+  );
 };

src/main.cc

@@ -9,8 +9,12 @@ int main(int argc, char *argv[]) {
 
   Vase vase = Vase(std::string(argv[1]));
 
+  auto matches = vase.regex_search("hello", {{0, 0}, {vase.root->lines, UINT64_MAX}}, "g");
+
   std::cout << "\n"
-            << vase.to_string()
+            << (int)vase.length() << " bytes\n"
+            << (int)vase.root->lines << " lines\n"
+            << (int)matches.size() << " matches\n"
             << "\n";
 
   return 0;

src/vase/buffer/append.cc

@@ -10,7 +10,7 @@ AppendBuffer::~AppendBuffer() {
     free(p);
 }
 
-uint32_t AppendBuffer::key(char c) {
+uint64_t AppendBuffer::append(char c) {
   if (t_offset == APPEND_CHUNK_SIZE) {
     t_current = (TChunk *)malloc(sizeof(TChunk));
     buf.push_back(t_current);
@@ -20,15 +20,15 @@ uint32_t AppendBuffer::key(char c) {
   return current_offset++;
 }
 
-uint32_t AppendBuffer::append(const char *text, uint32_t length) {
+uint64_t AppendBuffer::append(const char *text, uint64_t length) {
-  uint32_t start = current_offset;
+  uint64_t start = current_offset;
   while (length > 0) {
     if (t_offset == APPEND_CHUNK_SIZE) {
       t_current = (TChunk *)malloc(sizeof(TChunk));
       buf.push_back(t_current);
       t_offset = 0;
     }
-    uint32_t copy = std::min(length, APPEND_CHUNK_SIZE - t_offset);
+    uint64_t copy = std::min(length, APPEND_CHUNK_SIZE - t_offset);
     memcpy((*t_current) + t_offset, text, copy);
     t_offset += copy;
     current_offset += copy;
@@ -38,18 +38,18 @@ uint32_t AppendBuffer::append(const char *text, uint32_t length) {
   return start;
 }
 
-const char *AppendBuffer::read(uint32_t pos, uint32_t *out_len) {
+const char *AppendBuffer::read(uint64_t pos, uint64_t *out_len) {
   if (pos >= current_offset)
     return nullptr;
-  uint32_t local_offset = pos % APPEND_CHUNK_SIZE;
+  uint64_t local_offset = pos % APPEND_CHUNK_SIZE;
   if (out_len) {
-    uint32_t remaining = current_offset - pos;
+    uint64_t remaining = current_offset - pos;
-    uint32_t until_chunk_end = APPEND_CHUNK_SIZE - local_offset;
+    uint64_t until_chunk_end = APPEND_CHUNK_SIZE - local_offset;
     *out_len = std::min(remaining, until_chunk_end);
   }
   return &(*buf[pos / APPEND_CHUNK_SIZE])[local_offset];
 }
 
-inline uint32_t AppendBuffer::length() {
+inline uint64_t AppendBuffer::length() {
   return current_offset;
 }

src/vase/buffer/original.cc

@@ -1,15 +1,36 @@
 #include "vase/buffer/original.h"
 #include "io/file.h"
 
-OriginalBuffer::OriginalBuffer(std::string path) {
+OriginalBuffer::OriginalBuffer() {
-  read_file(path.c_str(), &buf, &len);
+  char tmp_path[] = "/tmp/tbuf.XXXXXX";
+  fd = mkstemp(tmp_path);
+  if (fd == -1)
+    exit(1);
+  unlink(tmp_path);
 }
 
 OriginalBuffer::~OriginalBuffer() {
-  free(buf);
+  if (buf)
+    munmap((char *)buf, len);
+  if (fd != -1)
+    close(fd);
 }
 
-const char *OriginalBuffer::read(uint32_t pos, uint32_t *out_len) {
+void OriginalBuffer::initialize() {
+  struct stat st;
+  if (fstat(fd, &st) == -1)
+    throw std::runtime_error("fstat failed");
+  len = (uint64_t)st.st_size;
+  buf = (const char *)mmap(nullptr, len, PROT_READ, MAP_PRIVATE, fd, 0);
+  if (buf == MAP_FAILED) {
+    buf = nullptr;
+    throw std::runtime_error("mmap failed");
+  }
+  close(fd);
+  fd = -1;
+}
+
+const char *OriginalBuffer::read(uint64_t pos, uint64_t *out_len) {
   if (pos >= len)
     return nullptr;
   if (out_len)
@@ -17,6 +38,6 @@ const char *OriginalBuffer::read(uint32_t pos, uint32_t *out_len) {
   return buf + pos;
 }
 
-uint32_t OriginalBuffer::length() {
+uint64_t OriginalBuffer::length() {
   return len;
 }

src/vase/iterators/chunk.cc

@@ -11,15 +11,18 @@ ChunkIterator::~ChunkIterator() {
   Shard::release(root);
 }
 
-void ChunkIterator::seek_offset(uint32_t offset) {
+void ChunkIterator::seek_offset(uint64_t offset) {
   stack.clear();
   petal = nullptr;
   petal_offset = 0;
+  global_offset = 0;
+  global_line = 0;
+  at_end = false;
   if (!root)
     return;
   if (offset >= root->length)
     offset = root->length - 1;
-  uint32_t target = offset;
+  uint64_t target = offset;
   Shard *curr = root;
   while (curr) {
     if (curr->kind == Shard::ShardKind::Petal) {
@@ -29,7 +32,7 @@ void ChunkIterator::seek_offset(uint32_t offset) {
       return;
     } else {
       auto *b = (Branch *)curr;
-      uint32_t left_len = b->left->length;
+      uint64_t left_len = b->left->length;
       if (target < left_len) {
         if (dir == Direction::Forward)
           stack.push_back(b->right);
@@ -39,6 +42,7 @@ void ChunkIterator::seek_offset(uint32_t offset) {
         if (dir == Direction::Backward)
           stack.push_back(b->left);
         global_offset += left_len;
+        global_line += b->left->lines;
         curr = b->right;
       }
     }
@@ -46,31 +50,40 @@ void ChunkIterator::seek_offset(uint32_t offset) {
   std::unreachable();
 }
 
-void ChunkIterator::seek_line(uint32_t line) {
+void ChunkIterator::seek_line(uint64_t line) {
   stack.clear();
   petal = nullptr;
   petal_offset = 0;
+  global_offset = 0;
+  at_end = false;
   bool last_line = false;
   if (!root)
     return;
+  if (dir == Direction::Backward) {
     if (line > root->lines + 1)
       line = root->lines + 1;
     if (line == root->lines + 1)
       last_line = true;
+  } else {
+    if (line > root->lines)
+      line = root->lines;
+    if (line == root->lines)
+      last_line = true;
+  }
   Shard *curr = root;
   while (curr) {
     if (curr->kind == Shard::ShardKind::Petal) {
       petal = (Petal *)curr;
-      if (last_line) {
+      if (last_line && dir == Direction::Backward) {
         petal_offset = petal->length;
         global_offset += petal->length;
       } else {
         const char *text = nullptr;
-        uint32_t remaining = 0;
+        uint64_t remaining = 0;
-        uint32_t offset = 0;
+        uint64_t offset = 0;
         while (line) {
           if (!text) {
-            uint32_t got = 0;
+            uint64_t got = 0;
             text = petal->source->read(petal->pos + offset, &got);
             remaining = std::min(got, petal->length - offset);
           }
@@ -87,13 +100,15 @@ void ChunkIterator::seek_line(uint32_t line) {
         }
         if (dir == Direction::Backward)
           --offset;
+        if (last_line && dir == Direction::Forward)
+          at_end = true;
         petal_offset = offset;
         global_offset += offset;
       }
       return;
     } else {
       auto *b = (Branch *)curr;
-      uint32_t left_lines = b->left->lines;
+      uint64_t left_lines = b->left->lines;
       if (line <= left_lines) {
         if (dir == Direction::Forward)
           stack.push_back(b->right);
@@ -110,30 +125,41 @@ void ChunkIterator::seek_line(uint32_t line) {
   std::unreachable();
 }
 
-uint32_t ChunkIterator::byte_offset() {
+uint64_t ChunkIterator::byte_offset() {
   return global_offset;
 }
 
-bool ChunkIterator::next(const char **data, uint32_t *out_len) {
+uint64_t ChunkIterator::line_offset() {
+  return global_line;
+}
+
+bool ChunkIterator::next(const char **data, uint64_t *out_len) {
   if (dir == Direction::Forward) {
     while (true) {
       if (petal) {
         if (petal_offset == petal->length) {
+          if (at_end) {
+            *data = nullptr;
+            *out_len = 0;
+            at_end = false;
+            return true;
+          }
           petal = nullptr;
           continue;
         }
-        uint32_t remaining = petal->length - petal_offset;
+        uint64_t remaining = petal->length - petal_offset;
-        uint32_t got = 0;
+        uint64_t got = 0;
         const char *chunk = petal->source->read(petal->pos + petal_offset, &got);
         if (got == 0) {
           petal = nullptr;
           petal_offset = 0;
           return false;
         }
-        uint32_t take = std::min(got, remaining);
+        uint64_t take = std::min(got, remaining);
         *data = chunk;
         *out_len = take;
         petal_offset += take;
+        global_offset += take;
         return true;
       }
       if (stack.empty())
@@ -155,17 +181,19 @@ bool ChunkIterator::next(const char **data, uint32_t *out_len) {
           petal = nullptr;
           continue;
         }
-        uint32_t got = 0;
+        uint64_t got = 0;
         *data = petal->source->read(petal->pos, &got);
         if (petal_offset > got) {
-          uint32_t got2 = 0;
+          uint64_t got2 = 0;
           *data = petal->source->read(petal->pos + got, &got2);
           *out_len = std::min(got2, petal_offset - got);
           petal_offset = got;
+          global_offset -= *out_len;
           return true;
         } else {
           *out_len = std::min(got, petal_offset);
           petal_offset = 0;
+          global_offset -= *out_len;
           return true;
         }
       }

src/vase/iterators/line.cc

@@ -1,55 +1,86 @@
 #include "vase/iterators/line.h"
 
-LineIterator::LineIterator(Shard *r, uint32_t start_line, Direction dir)
+LineIterator::LineIterator(Shard *r, uint64_t start_line, Direction dir)
     : it(r, dir), dir(dir) {
-  it.seek_line(start_line + (dir == Direction::Backward));
+  int b = start_line == UINT64_MAX ? 0 : dir == Direction::Backward;
-  if (!it.next(&chunk, &len))
+  it.seek_line(start_line + b);
+  if (!it.next(&chunk, &len)) {
     chunk = nullptr;
+    return;
+  }
+  if (chunk == nullptr)
+    at_end = true;
+  if (dir == Direction::Forward)
+    chunk_offset = it.byte_offset() - len;
+  else
+    chunk_offset = it.byte_offset();
 }
 
-uint32_t LineIterator::byte_offset() {
+uint64_t LineIterator::byte_offset() {
-  return 0;
+  return offset;
 }
 
 bool LineIterator::next(std::string &line) {
   line.clear();
+  if (at_end) {
+    offset = chunk_offset;
+    at_end = false;
+    return true;
+  }
   if (!chunk)
     return false;
   if (dir == Direction::Forward) {
+    offset = chunk_offset;
     while (true) {
       const char *nl = (const char *)memchr(chunk, '\n', len);
       if (!nl) {
         if (len && chunk[len - 1] == '\r')
           --len;
         line.append(chunk, len);
+        chunk_offset += len;
         if (!it.next(&chunk, &len)) {
           chunk = nullptr;
           return true;
         }
+        if (chunk == nullptr)
+          return true;
+        chunk_offset = it.byte_offset() - len;
         continue;
       }
       const char *end = nl;
       if (end > chunk && *(end - 1) == '\r')
         --end;
       line.append(chunk, end);
-      uint32_t consumed = (nl - chunk) + 1;
+      uint64_t consumed = (nl - chunk) + 1;
       chunk += consumed;
       len -= consumed;
+      chunk_offset += consumed;
       return true;
     }
   } else {
     while (true) {
+#if defined(__GLIBC__) || defined(__APPLE__)
       const char *nl = (const char *)memrchr(chunk, '\n', len);
+#else
+      const char *nl = nullptr;
+      uint64_t i = len;
+      while (i--) {
+        if (chunk[i] == '\n') {
+          nl = chunk + i;
+          break;
+        }
+      }
+#endif
       if (!nl) {
-        if (len && chunk[len - 1] == '\n')
-          --len;
         if (len && chunk[len - 1] == '\r')
           --len;
         line.insert(0, chunk, len);
+        chunk_offset -= len;
         if (!it.next(&chunk, &len)) {
           chunk = nullptr;
           return true;
         }
+        chunk_offset = it.byte_offset();
         continue;
       }
       const char *end = chunk + len;
@@ -59,6 +90,7 @@ bool LineIterator::next(std::string &line) {
         --line_end;
       line.insert(0, start, line_end - start);
       len = nl - chunk;
+      offset = chunk_offset + (start - chunk);
       return true;
     }
   }

src/vase/regex/api.cc

@@ -0,0 +1,151 @@
+#include "vase/vase.h"
+
+std::vector<ReplacePart> Vase::parse_replace(std::string_view s) {
+  std::vector<ReplacePart> parts;
+  std::string constant;
+  auto flush_constant = [&]() {
+    if (!constant.empty()) {
+      uint64_t lines = 0;
+      uint64_t pos = append->append(constant.data(), (uint64_t)constant.size());
+      parts.push_back(
+        ReplacePart{
+          .type = ReplacePart::PartType::Constant,
+          .value = new Petal((uint64_t)constant.size(), lines, append, pos)
+        }
+      );
+      constant.clear();
+    }
+  };
+  for (size_t i = 0; i < s.size(); ++i) {
+    char c = s[i];
+    if (c == '\\' && i + 1 < s.size() && s[i + 1] == '$') {
+      constant.push_back('$');
+      ++i;
+      continue;
+    }
+    if (c == '$' && i + 1 < s.size()) {
+      char next = s[i + 1];
+      if (next == '0') {
+        flush_constant();
+        parts.push_back(
+          ReplacePart{
+            .type = ReplacePart::PartType::FullMatch,
+            .value = (uint8_t)0
+          }
+        );
+        ++i;
+        continue;
+      }
+      if (next >= '1' && next <= '9') {
+        flush_constant();
+        parts.push_back(
+          ReplacePart{
+            .type = ReplacePart::PartType::CaptureGroup,
+            .value = (uint8_t)(next - '0')
+          }
+        );
+        ++i;
+        continue;
+      }
+    }
+    constant.push_back(c);
+  }
+  flush_constant();
+  return parts;
+}
+
+void Vase::regex_search_replace(
+  std::string_view pattern, Range range,
+  std::string_view replace, std::string_view options
+) {
+  std::vector<RegexMatch> matches = _regex_search(pattern, range, options);
+  if (matches.empty())
+    return;
+
+  std::vector<ReplacePart> replace_parts = parse_replace(replace);
+
+  std::vector<Shard *> pieces;
+  pieces.reserve(matches.size() * 2 + 1);
+
+  Shard *remaining = root;
+  Shard::retain(remaining);
+  uint64_t cursor = 0;
+
+  for (const RegexMatch &match : matches) {
+    uint64_t gap = match.start - cursor;
+    if (gap > 0) {
+      auto [keep, rest] = split_shard(remaining, gap);
+      Shard::release(remaining);
+      pieces.push_back(keep);
+      remaining = rest;
+    }
+
+    auto [dropped, rest2] = split_shard(remaining, match.end - match.start);
+    Shard::release(remaining);
+    remaining = rest2;
+
+    for (size_t i = 0; i < replace_parts.size(); ++i) {
+      const ReplacePart &part = replace_parts[i];
+      switch (part.type) {
+      case ReplacePart::PartType::Constant:
+        Shard::retain(std::get<Shard *>(part.value));
+        pieces.push_back(std::get<Shard *>(part.value));
+        break;
+      case ReplacePart::PartType::FullMatch:
+        Shard::retain(dropped);
+        pieces.push_back(dropped);
+        break;
+      case ReplacePart::PartType::CaptureGroup: {
+        uint8_t idx = std::get<uint8_t>(part.value);
+        if (idx <= 9) {
+          const RegexGroup &group = match.groups[idx - 1];
+          if (group.start != UINT32_MAX) {
+            uint64_t ls = group.start - match.start;
+            uint64_t le = group.end - match.start;
+            auto [a, b] = split_shard(dropped, ls);
+            auto [g, c] = split_shard(b, le - ls);
+            Shard::release(a);
+            Shard::release(b);
+            Shard::release(c);
+            pieces.push_back(g);
+          }
+        }
+        break;
+      }
+      }
+    }
+    Shard::release(dropped);
+    cursor = match.end;
+  }
+  pieces.push_back(remaining);
+
+  for (auto &part : replace_parts)
+    if (part.type == ReplacePart::PartType::Constant)
+      Shard::release(std::get<Shard *>(part.value));
+
+  std::vector<Shard *> compact;
+  compact.reserve(pieces.size());
+  for (Shard *p : pieces) {
+    if (p && p->length > 0)
+      compact.push_back(p);
+    else if (p)
+      Shard::release(p);
+  }
+
+  Shard *new_root = compact.empty() ? nullptr : build_balanced(compact.data(), 0, compact.size());
+  Shard::release(root);
+  root = new_root;
+}
+
+std::vector<Range> Vase::regex_search(
+  std::string_view pattern, Range range, std::string_view options
+) {
+  std::vector<RegexMatch> matches = _regex_search(pattern, range, options);
+  if (matches.empty())
+    return {};
+  std::vector<Range> result;
+  result.reserve(matches.size());
+  for (auto match : matches)
+    result.push_back({point_of(match.start), point_of(match.end)});
+  return result;
+}

src/vase/regex/core.cc

@@ -1,13 +1,10 @@
-#include "vase/search.h"
+#include "vase/vase.h"
-#include "vase/iterators/chunk.h"
 
-std::vector<RegexMatch> regex_search(
+std::vector<RegexMatch> Vase::_regex_search(
-  Shard *root, std::string_view pattern_str,
+  std::string_view pattern, Range range, std::string_view options
-  uint32_t start_offset, uint32_t end_offset,
-  std::string_view options
 ) {
   bool global = false;
-  uint32_t flags = PCRE2_MULTILINE;
+  uint64_t flags = PCRE2_MULTILINE;
 
   const char *dot = "(?:(?!\\n)\\X)";
 
@@ -43,12 +40,12 @@ std::vector<RegexMatch> regex_search(
   PCRE2_SIZE erroroffset;
 
   std::string out;
-  out.reserve(pattern_str.size() * 2);
+  out.reserve(pattern.size() * 2);
   bool escaped = false;
   bool in_class = false;
   bool in_quote = false;
-  for (size_t i = 0; i < pattern_str.size(); i++) {
+  for (size_t i = 0; i < pattern.size(); i++) {
-    char c = pattern_str[i];
+    char c = pattern[i];
     if (escaped) {
       out += c;
       escaped = false;
@@ -56,8 +53,8 @@ std::vector<RegexMatch> regex_search(
     }
     if (c == '\\') {
       out += c;
-      if (i + 1 < pattern_str.size()) {
+      if (i + 1 < pattern.size()) {
-        char next = pattern_str[i + 1];
+        char next = pattern[i + 1];
         if (next == 'Q')
           in_quote = true;
         else if (next == 'E')
@@ -104,40 +101,45 @@ std::vector<RegexMatch> regex_search(
 
   pcre2_match_data *match_data = pcre2_match_data_create_from_pattern(re, NULL);
 
+  uint64_t start_offset = offset_of(range.start);
+  uint64_t end_offset = offset_of(range.end);
+
+  std::cout << (int)start_offset << ":" << (int)end_offset;
+
   ChunkIterator it(root, Direction::Forward);
   it.seek_offset(start_offset);
 
   const char *data;
-  uint32_t length;
+  uint64_t length;
 
   char buf[2048];
 
-  uint32_t global_offset = start_offset;
+  uint64_t global_offset = start_offset;
-  int64_t offset = -1;
+  uint64_t offset = UINT64_MAX;
 
   auto record_match = [&](int rc, PCRE2_SIZE *ovector) {
-    if (global_offset + (uint32_t)ovector[1] > end_offset || ovector[0] == ovector[1])
+    if (global_offset + (uint64_t)ovector[1] > end_offset || ovector[0] == ovector[1])
       return;
     RegexMatch match{
-      .start = global_offset + (uint32_t)ovector[0],
+      .start = global_offset + (uint64_t)ovector[0],
-      .end = global_offset + (uint32_t)ovector[1]
+      .end = global_offset + (uint64_t)ovector[1]
     };
     for (int i = 1; i < rc && i <= 9; ++i) {
       PCRE2_SIZE s = ovector[2 * i];
       PCRE2_SIZE e = ovector[2 * i + 1];
       if (s != PCRE2_UNSET) {
-        match.groups[i].start = global_offset + (uint32_t)s;
+        match.groups[i].start = global_offset + (uint64_t)s;
-        match.groups[i].end = global_offset + (uint32_t)e;
+        match.groups[i].end = global_offset + (uint64_t)e;
       }
     }
     results.push_back(std::move(match));
   };
 
-  auto skip_to_next_line = [&](const char *&data, uint32_t &length, int64_t &offset, uint32_t &global_offset) {
+  auto skip_to_next_line = [&](const char *&data, uint64_t &length, uint64_t &offset, uint64_t &global_offset) {
     while (true) {
       const char *p = (const char *)memchr(data + offset, '\n', length - offset);
       if (p) {
-        uint32_t nl = p - data;
+        uint64_t nl = p - data;
         offset = nl + 1;
         return;
       }
@@ -150,7 +152,7 @@ std::vector<RegexMatch> regex_search(
   };
 
   while (global_offset < end_offset) {
-    if (offset == -1) {
+    if (offset == UINT64_MAX) {
       bool more = it.next(&data, &length);
       if (!more)
         break;
@@ -158,7 +160,7 @@ std::vector<RegexMatch> regex_search(
     }
 
     while (offset < length) {
-      if (offset == -1)
+      if (offset == UINT64_MAX)
         break;
 
       int rc = pcre2_match(
@@ -172,15 +174,15 @@ std::vector<RegexMatch> regex_search(
       );
 
       if (rc == PCRE2_ERROR_PARTIAL) {
-        uint32_t buflen = 0;
+        uint64_t buflen = 0;
 
         PCRE2_SIZE *ovector = pcre2_get_ovector_pointer(match_data);
-        uint32_t partial_start = ovector[0];
+        uint64_t partial_start = ovector[0];
-        uint32_t partial_length = length - partial_start;
+        uint64_t partial_length = length - partial_start;
 
         if (partial_length >= 2048) {
           global_offset += offset;
-          offset = -1;
+          offset = UINT64_MAX;
           continue;
         }
 
@@ -189,7 +191,7 @@ std::vector<RegexMatch> regex_search(
         memcpy(buf, data + partial_start, partial_length);
         buflen += partial_length;
 
-        offset = -1;
+        offset = UINT64_MAX;
         bool exhausted = false;
 
         while (true) {
@@ -201,7 +203,7 @@ std::vector<RegexMatch> regex_search(
             exhausted = true;
             break;
           }
-          uint32_t l = std::min(length, 2048 - buflen);
+          uint64_t l = std::min(length, 2048 - buflen);
           memcpy(buf + buflen, data, l);
           buflen += l;
 
@@ -235,7 +237,7 @@ std::vector<RegexMatch> regex_search(
         }
 
         if (exhausted) {
-          uint32_t search_from = 0;
+          uint64_t search_from = 0;
           while (search_from <= buflen) {
             int rc = pcre2_match(
               re,
@@ -251,7 +253,7 @@ std::vector<RegexMatch> regex_search(
             PCRE2_SIZE *ov = pcre2_get_ovector_pointer(match_data);
             record_match(rc, ov);
             if (global) {
-              search_from = (ov[1] == ov[0]) ? (uint32_t)ov[1] + 1 : (uint32_t)ov[1];
+              search_from = (ov[1] == ov[0]) ? (uint64_t)ov[1] + 1 : (uint64_t)ov[1];
             } else {
               const void *p = memchr(buf + ov[1], '\n', buflen - ov[1]);
               if (!p)
@@ -259,7 +261,7 @@ std::vector<RegexMatch> regex_search(
               search_from = (const char *)p - buf + 1;
             }
           }
-          offset = -1;
+          offset = UINT64_MAX;
         }
 
         continue;
@@ -267,7 +269,7 @@ std::vector<RegexMatch> regex_search(
         PCRE2_SIZE *ovector = pcre2_get_ovector_pointer(match_data);
         record_match(rc, ovector);
         if (global) {
-          if ((int64_t)ovector[1] == offset)
+          if (ovector[1] == offset)
             offset++;
           else
             offset = ovector[1];
@@ -285,7 +287,7 @@ std::vector<RegexMatch> regex_search(
     }
 
     global_offset += offset;
-    offset = -1;
+    offset = UINT64_MAX;
   }
 
   pcre2_match_data_free(match_data);

src/vase/shard.cc

@@ -112,7 +112,7 @@ Shard *merge(Shard *a, Shard *b) {
   return balance(new Branch(a, b));
 }
 
-std::pair<Shard *, Shard *> split_shard(Shard *n, uint32_t offset) {
+std::pair<Shard *, Shard *> split_shard(Shard *n, uint64_t offset) {
   if (!n)
     return {nullptr, nullptr};
   if (offset == 0) {
@@ -139,10 +139,10 @@ std::pair<Shard *, Shard *> split_shard(Shard *n, uint32_t offset) {
     }
   } else {
     Petal *p = (Petal *)n;
-    uint32_t count[2]{0};
+    uint64_t count[2]{0};
-    uint32_t read_offset = 0;
+    uint64_t read_offset = 0;
     while (read_offset < p->length) {
-      uint32_t got = 0;
+      uint64_t got = 0;
       const char *c = p->source->read(p->pos + read_offset, &got);
       const char *end = c + std::min(got, p->length - read_offset);
       const char *cursor = c;
@@ -152,14 +152,14 @@ std::pair<Shard *, Shard *> split_shard(Shard *n, uint32_t offset) {
           cursor = end;
           break;
         }
-        uint32_t nl_pos = read_offset + (uint32_t)(nl - c);
+        uint64_t nl_pos = read_offset + (uint64_t)(nl - c);
         if (nl_pos < offset)
           count[0]++;
         else
           count[1]++;
         cursor = nl + 1;
       }
-      read_offset += (uint32_t)(cursor - c);
+      read_offset += (uint64_t)(cursor - c);
     }
     auto left = new Petal(
       offset,
@@ -208,7 +208,7 @@ Shard *concat_shard(Shard *left, Shard *right) {
   return merge(left, right);
 }
 
-Shard *build_balanced(Shard **pieces, uint32_t lo, uint32_t hi) {
+Shard *build_balanced(Shard **pieces, uint64_t lo, uint64_t hi) {
   if (hi - lo == 1)
     return pieces[lo];
   size_t mid = lo + (hi - lo) / 2;
@@ -220,19 +220,34 @@ Shard *build_balanced(Shard **pieces, uint32_t lo, uint32_t hi) {
   return node;
 }
 
-Shard *create_shards(Buffer *o) {
+Shard *create_file_shards(std::string &path, OriginalBuffer *o) {
+  int dest_fd = o->fd;
+  if (dest_fd == -1)
+    return nullptr;
+  int src_fd = open(path.c_str(), O_RDONLY);
+  if (src_fd == -1)
+    return nullptr;
+  struct stat st;
+  if (fstat(src_fd, &st) == -1)
+    return nullptr;
+
+  uint64_t total = (uint64_t)st.st_size;
   std::vector<Shard *> pieces;
-  uint32_t pos = 0;
+  uint64_t pos = 0;
-  const uint32_t total = o->length();
   pieces.reserve((total + PETAL_SIZE_MAX - 1) / PETAL_SIZE_MAX);
+  char buf[PETAL_SIZE_MAX];
 
   while (pos < total) {
-    uint32_t len = 0;
+    uint64_t want = std::min(PETAL_SIZE_MAX, total - pos);
-    const char *data = o->read(pos, &len);
+    ssize_t got = pread(src_fd, buf, want, pos);
-    uint32_t take = std::min(len, PETAL_SIZE_MAX);
+    if (got <= 0) {
-    uint32_t lines = 0;
+      close(src_fd);
-    const char *p = data;
+      return nullptr;
-    const char *end = data + take;
+    }
+    uint64_t take = (uint64_t)got;
+    uint64_t lines = 0;
+    const char *p = buf;
+    const char *end = p + take;
     while (p < end) {
       const void *nl = memchr(p, '\n', end - p);
       if (!nl)
@@ -240,14 +255,23 @@ Shard *create_shards(Buffer *o) {
       lines++;
       p = (const char *)nl + 1;
     }
+    ssize_t written = write(dest_fd, buf, take);
+    if (written != (ssize_t)take) {
+      close(src_fd);
+      return nullptr;
+    }
     pieces.push_back(new Petal(take, lines, o, pos));
     pos += take;
   }
 
+  close(src_fd);
+
   if (pieces.empty())
     return nullptr;
+
+  o->initialize();
+
   if (pieces.size() == 1)
     return pieces[0];
-
   return build_balanced(pieces.data(), 0, pieces.size());
 }

src/vase/vase.cc

@@ -1,11 +1,11 @@
 #include "vase/vase.h"
 #include "utils/utils.h"
 #include "vase/iterators/line.h"
-#include "vase/search.h"
 
-Vase::Vase(std::string path)
+Vase::Vase(std::string path) {
-    : original(path), append(),
+  append = new AppendBuffer();
-      root(create_shards(&original)) {
+  original = new OriginalBuffer();
+  root = create_file_shards(path, original);
   history.push_back(root);
   Shard::retain(root);
   history_top = 0;
@@ -15,19 +15,42 @@ Vase::~Vase() {
   Shard::release(root);
   for (auto s : history)
     Shard::release(s);
+  delete original;
+  delete append;
 }
 
-uint32_t Vase::length() {
+uint64_t Vase::length() {
   return root->length;
 }
 
 std::string Vase::to_string() {
   std::string out;
-  flatten(root, out);
+  ChunkIterator it(root, Direction::Forward);
+  it.seek_offset(0);
+  const char *data;
+  uint64_t len;
+  while (it.next(&data, &len))
+    out.append(data, len);
   return out;
 }
 
-LineIterator Vase::iterate(uint32_t line) {
+std::string Vase::to_string(Range range) {
+  std::string out;
+  ChunkIterator it(root, Direction::Forward);
+  uint64_t start = offset_of(range.start);
+  it.seek_offset(start);
+  const char *data;
+  uint64_t len;
+  uint64_t remaining = offset_of(range.end) - start;
+  while (remaining && it.next(&data, &len)) {
+    uint64_t n = std::min(len, remaining);
+    out.append(data, n);
+    remaining -= n;
+  }
+  return out;
+}
+
+LineIterator Vase::iterate(uint64_t line) {
   return LineIterator(root, line, Direction::Forward);
 }
 
@@ -63,21 +86,40 @@ void Vase::snapshot() {
   history_top++;
 }
 
-void Vase::prune_history(uint32_t n) {
+void Vase::prune_history(uint64_t n) {
   n = std::min(n, history_top);
-  for (uint32_t i = 0; i < n; ++i)
+  for (uint64_t i = 0; i < n; ++i)
     Shard::release(history[i]);
   history.erase(history.begin(), history.begin() + n);
   history_top -= n;
 }
 
+bool Vase::save(std::string path) {
+  std::ofstream file(path, std::ios::binary);
+  if (!file)
+    return false;
+  ChunkIterator it(root, Direction::Forward);
+  it.seek_offset(0);
+  const char *data;
+  uint64_t len;
+  while (it.next(&data, &len)) {
+    file.write(data, len);
+    if (!file)
+      return false;
+  }
+  return true;
+}
+
+bool Vase::save_swap(std::string path) {
+}
+
 void Vase::insert(Point *point, char key) {
   if (key == '\n')
     *point = {point->row + 1, 0};
   else
     point->col++;
-  uint32_t pos = append.key(key);
+  uint64_t pos = append->append(key);
-  Shard *inserted = new Petal(1, key == '\n', &append, pos);
+  Shard *inserted = new Petal(1, key == '\n', append, pos);
   auto [left, right] = split_shard(root, offset_of(*point));
   Shard *left2 = append_leaf(left, inserted);
   Shard *new_root = concat_shard(left2, right);
@@ -89,21 +131,21 @@ void Vase::insert(Point *point, char key) {
   root = new_root;
 }
 
-void Vase::insert(Point *point, const char *data, uint32_t len) {
+void Vase::insert(Point *point, const char *data, uint64_t len) {
   while (len) {
-    uint32_t chunk_size = std::min<uint32_t>(len, PETAL_SIZE_MAX);
+    uint64_t chunk_size = std::min<uint64_t>(len, PETAL_SIZE_MAX);
     _insert(point, data, chunk_size);
     len -= chunk_size;
     data += chunk_size;
   }
 }
 
-void Vase::_insert(Point *point, const char *data, uint32_t len) {
+void Vase::_insert(Point *point, const char *data, uint64_t len) {
   if (len == 0)
     return;
-  uint32_t offset = offset_of(*point);
+  uint64_t offset = offset_of(*point);
-  uint32_t pos = append.append(data, len);
+  uint64_t pos = append->append(data, len);
-  uint32_t lines = 0;
+  uint64_t lines = 0;
   const char *start = data;
   const char *last_line = start;
   const char *end = start + len;
@@ -111,10 +153,10 @@ void Vase::_insert(Point *point, const char *data, uint32_t len) {
     ++lines;
     last_line = ++data;
   }
-  uint32_t col = 0;
+  uint64_t col = 0;
-  uint32_t remaining = end - last_line;
+  uint64_t remaining = end - last_line;
   while (remaining) {
-    uint32_t n = grapheme_next_character_break_utf8(last_line, remaining);
+    uint64_t n = grapheme_next_character_break_utf8(last_line, remaining);
     last_line += n;
     remaining -= n;
     ++col;
@@ -125,7 +167,7 @@ void Vase::_insert(Point *point, const char *data, uint32_t len) {
   } else {
     point->col += col;
   }
-  Shard *inserted = new Petal(len, lines, &append, pos);
+  Shard *inserted = new Petal(len, lines, append, pos);
   auto [left, right] = split_shard(root, offset);
   Shard *left2 = append_leaf(left, inserted);
   Shard *new_root = concat_shard(left2, right);
@@ -137,20 +179,20 @@ void Vase::_insert(Point *point, const char *data, uint32_t len) {
   root = new_root;
 }
 
-void Vase::erase(Point *point, int64_t amount) {
+void Vase::erase(Point *point, uint64_t amount, Direction dir) {
   if (amount == 0)
     return;
   Point start = *point;
   Point end = *point;
-  if (amount < 0)
+  if (dir == Direction::Forward)
-    move_clusters(&start, amount);
+    move_clusters(&end, amount, Direction::Forward);
   else
-    move_clusters(&end, amount);
+    move_clusters(&start, amount, Direction::Backward);
-  uint32_t start_offset = offset_of(start);
+  uint64_t start_offset = offset_of(start);
-  uint32_t end_offset = offset_of(end);
+  uint64_t end_offset = offset_of(end);
   if (start_offset > end_offset)
     std::swap(start_offset, end_offset);
-  uint32_t count = end_offset - start_offset;
+  uint64_t count = end_offset - start_offset;
   auto [a, b] = split_shard(root, start_offset);
   auto [d, c] = split_shard(b, count);
   Shard *new_root = concat_shard(a, c);
@@ -160,16 +202,16 @@ void Vase::erase(Point *point, int64_t amount) {
   Shard::release(d);
   Shard::release(root);
   root = new_root;
-  if (amount < 0)
+  if (dir == Direction::Backward)
     *point = start;
 }
 
 void Vase::erase(Range range) {
   Point start = range.start;
   Point end = range.end;
-  uint32_t start_offset = offset_of(start);
+  uint64_t start_offset = offset_of(start);
-  uint32_t end_offset = offset_of(end);
+  uint64_t end_offset = offset_of(end);
-  uint32_t count = end_offset - start_offset;
+  uint64_t count = end_offset - start_offset;
   auto [a, b] = split_shard(root, start_offset);
   auto [d, c] = split_shard(b, count);
   Shard *new_root = concat_shard(a, c);
@@ -181,40 +223,21 @@ void Vase::erase(Range range) {
   root = new_root;
 }
 
-void Vase::replace(Range range, const char *data, uint32_t len) {
+void Vase::replace(Range range, const char *data, uint64_t len) {
   erase(range);
   insert(&range.start, data, len);
 }
 
-void Vase::flatten(Shard *s, std::string &out) {
+uint64_t Vase::offset_of(Point point) {
-  if (s->kind == Shard::ShardKind::Petal) {
-    auto *p = (Petal *)s;
-    uint32_t remaining = p->length;
-    uint32_t pos = p->pos;
-    while (remaining) {
-      uint32_t got;
-      const char *data = p->source->read(pos, &got);
-      uint32_t take = std::min(got, remaining);
-      out.append(data, take);
-      remaining -= take;
-      pos += take;
-    }
-  } else {
-    auto *b = (Branch *)s;
-    flatten(b->left, out);
-    flatten(b->right, out);
-  }
-}
-
-uint32_t Vase::offset_of(Point point) {
   LineIterator it(root, point.row, Direction::Forward);
+
   std::string line;
-  uint32_t offset = 0;
+  uint64_t offset = 0;
   if (it.next(line)) {
     const char *ptr = line.data();
-    uint32_t remaining = line.length();
+    uint64_t remaining = line.length();
     while (point.col && remaining) {
-      uint32_t next_len = grapheme_next_character_break_utf8(ptr, remaining);
+      uint64_t next_len = grapheme_next_character_break_utf8(ptr, remaining);
       remaining -= next_len;
       ptr += next_len;
       offset += next_len;
@@ -224,29 +247,78 @@ uint32_t Vase::offset_of(Point point) {
   return it.byte_offset() + offset;
 }
 
-void Vase::move_clusters(Point *point, int64_t amount) {
+Point Vase::point_of(uint64_t offset) {
+  ChunkIterator it(root, Direction::Backward);
+  it.seek_offset(offset);
+  Point p;
+  p.row = it.line_offset();
+  std::string line;
+  const char *chunk;
+  uint64_t len = 0;
+  if (!it.next(&chunk, &len))
+    return p;
+  while (true) {
+#if defined(__GLIBC__) || defined(__APPLE__)
+    const char *nl = (const char *)memrchr(chunk, '\n', len);
+#else
+    const char *nl = nullptr;
+    uint64_t i = len;
+    while (i--) {
+      if (chunk[i] == '\n') {
+        nl = chunk + i;
+        break;
+      }
+    }
+#endif
+    if (!nl) {
+      if (len && chunk[len - 1] == '\r')
+        --len;
+      line.insert(0, chunk, len);
+      if (!it.next(&chunk, &len))
+        break;
+      continue;
+    }
+    const char *end = chunk + len;
+    const char *start = nl + 1;
+    const char *line_end = end;
+    if (line_end > start && *(line_end - 1) == '\r')
+      --line_end;
+    line.insert(0, start, line_end - start);
+    break;
+  }
+  const char *ptr = line.data();
+  uint64_t remaining = line.length();
+  while (remaining) {
+    uint64_t next_len = grapheme_next_character_break_utf8(ptr, remaining);
+    remaining -= next_len;
+    ptr += next_len;
+    p.col++;
+  }
+  return p;
+}
+
+void Vase::move_clusters(Point *point, uint64_t amount, Direction dir) {
   if (amount == 0)
     return;
-  if (amount < 0) {
+  if (dir == Direction::Backward) {
-    amount = -amount;
     LineIterator it(root, point->row, Direction::Backward);
-    while (amount > 0) {
+    while (amount) {
       std::string line;
       if (!it.next(line))
         return;
-      std::vector<uint32_t> clusters;
+      std::vector<uint64_t> clusters;
       const char *ptr = line.data();
-      uint32_t remaining = line.size();
+      uint64_t remaining = line.size();
-      uint32_t byte = 0;
+      uint64_t byte = 0;
       while (remaining) {
         clusters.push_back(byte);
-        uint32_t len =
+        uint64_t len =
           grapheme_next_character_break_utf8(ptr, remaining);
         ptr += len;
         remaining -= len;
         byte += len;
       }
-      while (amount > 0 && point->col > 0) {
+      while (amount && point->col) {
         point->col--;
         amount--;
       }
@@ -260,29 +332,29 @@ void Vase::move_clusters(Point *point, int64_t amount) {
     }
   } else {
     LineIterator it(root, point->row, Direction::Forward);
-    while (amount > 0) {
+    while (amount) {
       std::string line;
       if (!it.next(line))
         return;
-      if (point->col > 0 || amount > 0) {
+      if (point->col || amount) {
         const char *ptr = line.data();
-        uint32_t remaining = line.size();
+        uint64_t remaining = line.size();
-        uint32_t col = 0;
+        uint64_t col = 0;
         while (col < point->col && remaining) {
-          uint32_t len = grapheme_next_character_break_utf8(ptr, remaining);
+          uint64_t len = grapheme_next_character_break_utf8(ptr, remaining);
           ptr += len;
           remaining -= len;
           col++;
         }
-        while (amount > 0 && remaining) {
+        while (amount && remaining) {
-          uint32_t len = grapheme_next_character_break_utf8(ptr, remaining);
+          uint64_t len = grapheme_next_character_break_utf8(ptr, remaining);
           ptr += len;
           remaining -= len;
           point->col++;
           amount--;
         }
       }
-      if (amount > 0) {
+      if (amount) {
         point->row++;
         point->col = 0;
         amount--;
@@ -300,11 +372,11 @@ void Vase::clamp(Point *point) {
     point->col = 0;
     return;
   }
-  uint32_t clusters = 0;
+  uint64_t clusters = 0;
   const char *ptr = line.data();
-  uint32_t remaining = line.size();
+  uint64_t remaining = line.size();
   while (remaining) {
-    uint32_t len = grapheme_next_character_break_utf8(ptr, remaining);
+    uint64_t len = grapheme_next_character_break_utf8(ptr, remaining);
     ptr += len;
     remaining -= len;
     clusters++;
@@ -313,156 +385,14 @@ void Vase::clamp(Point *point) {
     point->col = clusters;
 }
 
-void Vase::move_lines(Point *point, int64_t amount) {
+void Vase::move_lines(Point *point, uint64_t amount, Direction dir) {
-  if (point->row + amount < 0)
+  if (dir == Direction::Forward) {
-    return;
     point->row += amount;
+  } else {
+    if (amount > point->row)
+      point->row = 0;
+    else
+      point->row -= amount;
+  }
   clamp(point);
 }
-
-struct ReplacePart {
-  enum struct PartType {
-    FullMatch,
-    CaptureGroup,
-    Constant
-  } type;
-
-  std::variant<uint8_t, Shard *> value;
-};
-
-std::vector<ReplacePart> parse_replace(AppendBuffer &buf, std::string_view s) {
-  std::vector<ReplacePart> parts;
-  std::string constant;
-  auto flush_constant = [&]() {
-    if (!constant.empty()) {
-      uint32_t lines = 0;
-      uint32_t pos = buf.append(constant.data(), (uint32_t)constant.size());
-      parts.push_back(
-        ReplacePart{
-          .type = ReplacePart::PartType::Constant,
-          .value = new Petal((uint32_t)constant.size(), lines, &buf, pos)
-        }
-      );
-      constant.clear();
-    }
-  };
-  for (size_t i = 0; i < s.size(); ++i) {
-    char c = s[i];
-    if (c == '\\' && i + 1 < s.size() && s[i + 1] == '$') {
-      constant.push_back('$');
-      ++i;
-      continue;
-    }
-    if (c == '$' && i + 1 < s.size()) {
-      char next = s[i + 1];
-      if (next == '0') {
-        flush_constant();
-        parts.push_back(
-          ReplacePart{
-            .type = ReplacePart::PartType::FullMatch,
-            .value = (uint8_t)0
-          }
-        );
-        ++i;
-        continue;
-      }
-      if (next >= '1' && next <= '9') {
-        flush_constant();
-        parts.push_back(
-          ReplacePart{
-            .type = ReplacePart::PartType::CaptureGroup,
-            .value = (uint8_t)(next - '0')
-          }
-        );
-        ++i;
-        continue;
-      }
-    }
-    constant.push_back(c);
-  }
-  flush_constant();
-  return parts;
-}
-
-void Vase::regex_search_replace(
-  std::string_view pattern, Range range,
-  std::string_view replace, std::string_view options
-) {
-  std::vector<RegexMatch> matches = regex_search(root, pattern, offset_of(range.start), offset_of(range.end), options);
-  if (matches.empty())
-    return;
-
-  std::vector<ReplacePart> replace_parts = parse_replace(append, replace);
-
-  std::vector<Shard *> pieces;
-  pieces.reserve(matches.size() * 2 + 1);
-
-  Shard *remaining = root;
-  Shard::retain(remaining);
-  uint32_t cursor = 0;
-
-  for (const RegexMatch &match : matches) {
-    uint32_t gap = match.start - cursor;
-    if (gap > 0) {
-      auto [keep, rest] = split_shard(remaining, gap);
-      Shard::release(remaining);
-      pieces.push_back(keep);
-      remaining = rest;
-    }
-
-    auto [dropped, rest2] = split_shard(remaining, match.end - match.start);
-    Shard::release(remaining);
-    remaining = rest2;
-
-    for (size_t i = 0; i < replace_parts.size(); ++i) {
-      const ReplacePart &part = replace_parts[i];
-      switch (part.type) {
-      case ReplacePart::PartType::Constant:
-        Shard::retain(std::get<Shard *>(part.value));
-        pieces.push_back(std::get<Shard *>(part.value));
-        break;
-      case ReplacePart::PartType::FullMatch:
-        Shard::retain(dropped);
-        pieces.push_back(dropped);
-        break;
-      case ReplacePart::PartType::CaptureGroup: {
-        uint8_t idx = std::get<uint8_t>(part.value);
-        if (idx <= 9) {
-          const RegexGroup &group = match.groups[idx - 1];
-          if (group.start != UINT32_MAX) {
-            uint32_t ls = group.start - match.start;
-            uint32_t le = group.end - match.start;
-            auto [a, b] = split_shard(dropped, ls);
-            auto [g, c] = split_shard(b, le - ls);
-            Shard::release(a);
-            Shard::release(b);
-            Shard::release(c);
-            pieces.push_back(g);
-          }
-        }
-        break;
-      }
-      }
-    }
-    Shard::release(dropped);
-    cursor = match.end;
-  }
-  pieces.push_back(remaining);
-
-  for (auto &part : replace_parts)
-    if (part.type == ReplacePart::PartType::Constant)
-      Shard::release(std::get<Shard *>(part.value));
-
-  std::vector<Shard *> compact;
-  compact.reserve(pieces.size());
-  for (Shard *p : pieces) {
-    if (p && p->length > 0)
-      compact.push_back(p);
-    else if (p)
-      Shard::release(p);
-  }
-
-  Shard *new_root = compact.empty() ? nullptr : build_balanced(compact.data(), 0, compact.size());
-  Shard::release(root);
-  root = new_root;
-}