Rearrange project files.

src/internal/vase/iterators/line.cc

@@ -0,0 +1,73 @@
+#include "internal/vase/iterators/line.h"
+
+LineIterator::LineIterator(Shard *root, uint64_t line_num, Direction dir)
+    : it(root, dir), dir(dir) {
+  it.seek_line(line_num);
+  it.next(&chunk, &len);
+  current_offset = it.byte_offset();
+  last_line_offset = current_offset;
+}
+
+bool LineIterator::next(std::string *line) {
+  if (!line || !chunk)
+    return false;
+  last_line_offset = current_offset;
+  line->clear();
+  if (dir == Direction::Forward) {
+  retry_forward:
+    const char *nl = (const char *)memchr(chunk, '\n', len);
+    if (!nl) {
+      if (len && chunk[len - 1] == '\r')
+        len--;
+      line->append(chunk, len);
+      current_offset += len;
+      if (!it.next(&chunk, &len))
+        return true;
+      goto retry_forward;
+    }
+    const char *end = nl;
+    if (end - chunk > 0 && *(end - 1) == '\r')
+      end--;
+    line->append(chunk, end);
+    size_t consumed = (nl - chunk) + 1;
+    chunk += consumed;
+    len -= consumed;
+    current_offset += consumed;
+    return true;
+  } else {
+  retry_backward:
+#if defined(__GLIBC__) || defined(__APPLE__) || defined(__FreeBSD__)
+    const char *nl = (const char *)memrchr(chunk, '\n', len);
+#else
+    const char *nl = nullptr;
+    const char *p = chunk + len;
+    while (!nl && p != chunk)
+      if (*(--p) == '\n')
+        nl = p;
+#endif
+    if (!nl) {
+      if (len && chunk[len - 1] == '\r')
+        len--;
+      line->insert(0, chunk, len);
+      current_offset -= len;
+      if (!it.next(&chunk, &len))
+        return true;
+      goto retry_backward;
+    }
+    const char *start = nl + 1;
+    const char *line_end = chunk + len;
+    const size_t consumed = line_end - nl;
+    const char *end = line_end;
+    if (end > start && *(end - 1) == '\r')
+      end--;
+    if (end > start)
+      line->insert(0, start, end - start);
+    len = nl - chunk;
+    current_offset -= consumed;
+    return true;
+  }
+}
+
+uint64_t LineIterator::byte_offset() {
+  return last_line_offset;
+}

src/internal/vase/iterators/petal.cc

@@ -0,0 +1,158 @@
+#include "internal/vase/iterators/petal.h"
+
+PetalIterator::PetalIterator(Shard *r, Direction dir)
+    : dir(dir), root(r) {
+  if (!root)
+    return;
+}
+
+void PetalIterator::seek_offset(uint64_t offset) {
+  stack.clear();
+  petal = nullptr;
+  global_offset = 0;
+  last_offset = 0;
+  global_line = 0;
+  if (!root)
+    return;
+  if (offset >= root->length)
+    offset = root->length - 1;
+  uint64_t target = offset;
+  Shard *curr = root;
+  while (curr) {
+    if (curr->kind == Shard::Kind::Petal) {
+      petal = (Petal *)curr;
+      petal_offset = target;
+      global_offset += target;
+      last_offset = global_offset;
+      return;
+    } else {
+      auto *b = (Branch *)curr;
+      uint64_t left_len = b->left->length;
+      if (target < left_len) {
+        if (dir == Direction::Forward)
+          stack.push_back(b->right);
+        curr = b->left;
+      } else {
+        target -= left_len;
+        if (dir == Direction::Backward)
+          stack.push_back(b->left);
+        global_offset += left_len;
+        global_line += b->left->lines;
+        curr = b->right;
+      }
+    }
+  }
+  std::unreachable();
+}
+
+void PetalIterator::seek_line(uint64_t line) {
+  stack.clear();
+  petal = nullptr;
+  global_offset = 0;
+  last_offset = 0;
+  bool last_line = false;
+  if (!root)
+    return;
+  if (line > root->lines)
+    line = root->lines;
+  if (line == root->lines)
+    last_line = true;
+  if (!last_line && dir == Direction::Backward)
+    line++;
+  Shard *curr = root;
+  while (curr) {
+    if (curr->kind == Shard::Kind::Petal) {
+      petal = (Petal *)curr;
+      if (last_line && dir == Direction::Backward) {
+        petal_offset = petal->length;
+        global_offset += petal->length;
+      } else {
+        const char *text = petal->source->read(petal->pos);
+        uint64_t offset = 0;
+        while (line) {
+          const char *c = (const char *)memchr(text, '\n', petal->length - offset);
+          if (!c)
+            throw std::runtime_error("leaf line count is wrong.");
+          offset += (c - text) + 1;
+          text = c + 1;
+          line--;
+        }
+        if (dir == Direction::Backward)
+          --offset;
+        petal_offset = offset;
+        global_offset += offset;
+      }
+      last_offset = global_offset;
+      return;
+    } else {
+      auto *b = (Branch *)curr;
+      uint64_t left_lines = b->left->lines;
+      if (line <= left_lines) {
+        if (dir == Direction::Forward)
+          stack.push_back(b->right);
+        curr = b->left;
+      } else {
+        line -= left_lines;
+        if (dir == Direction::Backward)
+          stack.push_back(b->left);
+        global_offset += b->left->length;
+        curr = b->right;
+      }
+    }
+  }
+  std::unreachable();
+}
+
+Petal *PetalIterator::_next(uint64_t *offset) {
+  while (true) {
+    if (petal) {
+      auto ret = petal;
+      last_offset = global_offset;
+      if (dir == Direction::Forward)
+        global_offset += petal_offset;
+      else
+        global_offset -= petal_offset;
+      petal = nullptr;
+      *offset = petal_offset;
+      return ret;
+    }
+    if (stack.empty())
+      return nullptr;
+    auto s = stack.back();
+    stack.pop_back();
+    while (s->kind == Shard::Kind::Branch) {
+      Branch *b = (Branch *)s;
+      if (dir == Direction::Forward) {
+        stack.push_back(b->right);
+        s = b->left;
+      } else {
+        stack.push_back(b->left);
+        s = b->right;
+      }
+    }
+    petal = (Petal *)s;
+    petal_offset = dir == Direction::Forward ? 0 : petal->length;
+  }
+}
+
+bool PetalIterator::next(const char **data, uint64_t *out_len) {
+  uint64_t offset = 0;
+  Petal *p = _next(&offset);
+  if (!p) {
+    *data = nullptr;
+    *out_len = 0;
+    return false;
+  }
+  if (dir == Direction::Forward) {
+    *out_len = p->length - offset;
+    *data = p->source->read(p->pos + offset);
+  } else {
+    *out_len = offset;
+    *data = p->source->read(p->pos);
+  }
+  return true;
+}
+
+uint64_t PetalIterator::byte_offset() {
+  return last_offset;
+}