Refactored the notion of "the current parsing context"

1 files changed, 151 insertions, 0 deletions

diff --git a/src/context.h b/src/context.h
new file mode 100644
index 00000000..0533536f
--- /dev/null
+++ b/src/context.h
@@ -0,0 +1,151 @@
+/*
+ * Copyright (c) 2003-2012, John Wiegley.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of New Artisans LLC nor the names of its
+ *   contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * @addtogroup data
+ */
+
+/**
+ * @file   context.h
+ * @author John Wiegley
+ *
+ * @ingroup data
+ */
+#ifndef _CONTEXT_H
+#define _CONTEXT_H
+
+#include "utils.h"
+#include "times.h"
+
+namespace ledger {
+
+class journal_t;
+class account_t;
+class scope_t;
+
+class parse_context_t
+{
+public:
+  static const std::size_t MAX_LINE = 4096;
+
+  shared_ptr<std::istream> stream;
+
+  path             pathname;
+  path             current_directory;
+  journal_t *      journal;
+  account_t *      master;
+  scope_t *        scope;
+  char             linebuf[MAX_LINE + 1];
+  istream_pos_type line_beg_pos;
+  istream_pos_type curr_pos;
+  std::size_t      linenum;
+  std::size_t      errors;
+  std::size_t      count;
+  std::size_t      sequence;
+
+  explicit parse_context_t(shared_ptr<std::istream> _stream,
+                           const path& cwd)
+    : stream(_stream), current_directory(cwd), master(NULL),
+      scope(NULL), linenum(0), errors(0), count(0), sequence(1) {}
+
+  parse_context_t(const parse_context_t& context)
+   : stream(context.stream),
+     pathname(context.pathname),
+     current_directory(context.current_directory),
+     journal(context.journal),
+     master(context.master),
+     scope(context.scope),
+     line_beg_pos(context.line_beg_pos),
+     curr_pos(context.curr_pos),
+     linenum(context.linenum),
+     errors(context.errors),
+     count(context.count),
+     sequence(context.sequence) {
+    std::memcpy(linebuf, context.linebuf, MAX_LINE);
+  }
+
+  string location() const {
+    return file_context(pathname, linenum);
+  }
+
+  void warning(const string& what) const {
+    warning_func(location() + what);
+  }
+};
+
+inline parse_context_t open_for_reading(const path& pathname,
+                                        const path& cwd)
+{
+  path filename = resolve_path(pathname);
+
+  if (! exists(filename))
+    throw_(std::runtime_error,
+           _("Cannot read journal file %1") << filename);
+
+  path parent(filesystem::absolute(pathname, cwd).parent_path());
+  shared_ptr<std::istream> stream(new ifstream(filename));
+  parse_context_t context(stream, parent);
+  context.pathname = filename;
+  return context;
+}
+
+class parse_context_stack_t
+{
+  std::list<parse_context_t> parsing_context;
+
+public:
+  void push(shared_ptr<std::istream> stream,
+            const path& cwd = filesystem::current_path()) {
+    parsing_context.push_front(parse_context_t(stream, cwd));
+  }
+  void push(const path& pathname,
+            const path& cwd = filesystem::current_path()) {
+    parsing_context.push_front(open_for_reading(pathname, cwd));
+  }
+
+  void push(const parse_context_t& context) {
+    parsing_context.push_front(context);
+  }
+
+  void pop() {
+    assert(! parsing_context.empty());
+    parsing_context.pop_front();
+  }
+
+  parse_context_t& get_current() {
+    assert(! parsing_context.empty());
+    return parsing_context.front();
+  }
+};
+
+} // namespace ledger
+
+#endif // _CONTEXT_H