1 files changed, 163 insertions, 0 deletions
diff --git a/libartbase/base/indenter.h b/libartbase/base/indenter.h
new file mode 100644
index 00000000000..850b7c4f737
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+++ b/libartbase/base/indenter.h
@@ -0,0 +1,163 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_LIBARTBASE_BASE_INDENTER_H_
+#define ART_LIBARTBASE_BASE_INDENTER_H_
+
+#include <ostream>
+#include <streambuf>
+
+#include <android-base/logging.h>
+
+#include "base/macros.h"
+
+namespace art {
+
+constexpr char kIndentChar =' ';
+constexpr size_t kIndentBy1Count = 2;
+
+class Indenter : public std::streambuf {
+ public:
+  Indenter(std::streambuf* out, char text, size_t count)
+      : indent_next_(true), out_sbuf_(out),
+        text_{text, text, text, text, text, text, text, text},
+        count_(count) {}
+
+ private:
+  std::streamsize xsputn(const char* s, std::streamsize n) OVERRIDE {
+    std::streamsize result = n;  // Aborts on failure.
+    const char* eol = static_cast<const char*>(memchr(s, '\n', n));
+    while (eol != nullptr) {
+      size_t to_write = eol + 1 - s;
+      Write(s, to_write);
+      s += to_write;
+      n -= to_write;
+      indent_next_ = true;
+      eol = static_cast<const char*>(memchr(s, '\n', n));
+    }
+    if (n != 0u) {
+      Write(s, n);
+    }
+    return result;
+  }
+
+  int_type overflow(int_type c) OVERRIDE {
+    if (UNLIKELY(c == std::char_traits<char>::eof())) {
+      out_sbuf_->pubsync();
+      return c;
+    }
+    char data[1] = { static_cast<char>(c) };
+    Write(data, 1u);
+    indent_next_ = (c == '\n');
+    return c;
+  }
+
+  int sync() {
+    return out_sbuf_->pubsync();
+  }
+
+  void Write(const char* s, std::streamsize n) {
+    if (indent_next_) {
+      size_t remaining = count_;
+      while (remaining != 0u) {
+        size_t to_write = std::min(remaining, sizeof(text_));
+        RawWrite(text_, to_write);
+        remaining -= to_write;
+      }
+      indent_next_ = false;
+    }
+    RawWrite(s, n);
+  }
+
+  void RawWrite(const char* s, std::streamsize n) {
+    size_t written = out_sbuf_->sputn(s, n);
+    s += written;
+    n -= written;
+    while (n != 0u) {
+      out_sbuf_->pubsync();
+      written = out_sbuf_->sputn(s, n);
+      CHECK_NE(written, 0u) << "Error writing to buffer. Disk full?";
+      s += written;
+      n -= written;
+    }
+  }
+
+  bool indent_next_;
+
+  // Buffer to write output to.
+  std::streambuf* const out_sbuf_;
+
+  // Text output as indent.
+  const char text_[8];
+
+  // Number of times text is output.
+  size_t count_;
+
+  friend class VariableIndentationOutputStream;
+
+  DISALLOW_COPY_AND_ASSIGN(Indenter);
+};
+
+class VariableIndentationOutputStream {
+ public:
+  explicit VariableIndentationOutputStream(std::ostream* os, char text = kIndentChar)
+      : indenter_(os->rdbuf(), text, 0u),
+        indented_os_(&indenter_) {
+  }
+
+  std::ostream& Stream() {
+    return indented_os_;
+  }
+
+  void IncreaseIndentation(size_t adjustment) {
+    indenter_.count_ += adjustment;
+  }
+
+  void DecreaseIndentation(size_t adjustment) {
+    DCHECK_GE(indenter_.count_, adjustment);
+    indenter_.count_ -= adjustment;
+  }
+
+ private:
+  Indenter indenter_;
+  std::ostream indented_os_;
+
+  DISALLOW_COPY_AND_ASSIGN(VariableIndentationOutputStream);
+};
+
+class ScopedIndentation {
+ public:
+  explicit ScopedIndentation(VariableIndentationOutputStream* vios,
+                             size_t adjustment = kIndentBy1Count)
+      : vios_(vios),
+        adjustment_(adjustment) {
+    vios_->IncreaseIndentation(adjustment_);
+  }
+
+  ~ScopedIndentation() {
+    vios_->DecreaseIndentation(adjustment_);
+  }
+
+ private:
+  VariableIndentationOutputStream* const vios_;
+  const size_t adjustment_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedIndentation);
+};
+
+}  // namespace art
+
+#endif  // ART_LIBARTBASE_BASE_INDENTER_H_