ceph/src/mgr/PyFormatter.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2015 Red Hat Inc
   7  *
   8  * Author: John Spray <john.spray@redhat.com>
   9  *
  10  * This is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License version 2.1, as published by the Free Software
  13  * Foundation.  See file COPYING.
  14  *
  15  */
  16
  17 #ifndef PY_FORMATTER_H_
  18 #define PY_FORMATTER_H_
  19
  20 // Python.h comes first because otherwise it clobbers ceph's assert
  21 #include <Python.h>
  22
  23 #include <stack>
  24 #include <string>
  25 #include <string_view>
  26 #include <sstream>
  27 #include <memory>
  28 #include <list>
  29
  30 #include "common/Formatter.h"
  31 #include "include/ceph_assert.h"
  32
  33 class PyFormatter : public ceph::Formatter
  34 {
  35 public:
  36   PyFormatter (const PyFormatter&) = delete;
  37   PyFormatter& operator= (const PyFormatter&) = delete;
  38   PyFormatter(bool pretty = false, bool array = false)
  39   {
  40     // It is forbidden to instantiate me outside of the GIL,
  41     // because I construct python objects right away
  42
  43     // Initialise cursor to an empty dict
  44     if (!array) {
  45       root = cursor = PyDict_New();
  46     } else {
  47       root = cursor = PyList_New(0);
  48     }
  49   }
  50
  51   ~PyFormatter() override
  52   {
  53     cursor = NULL;
  54     Py_DECREF(root);
  55     root = NULL;
  56   }
  57
  58   // Obscure, don't care.
  59   void open_array_section_in_ns(std::string_view name, const char *ns) override
  60   {ceph_abort();}
  61   void open_object_section_in_ns(std::string_view name, const char *ns) override
  62   {ceph_abort();}
  63
  64   void reset() override
  65   {
  66     const bool array = PyList_Check(root);
  67     Py_DECREF(root);
  68     if (array) {
  69       root = cursor = PyList_New(0);
  70     } else {
  71       root = cursor = PyDict_New();
  72     }
  73   }
  74
  75   void set_status(int status, const char* status_name) override {}
  76   void output_header() override {};
  77   void output_footer() override {};
  78   void enable_line_break() override {};
  79
  80   void open_array_section(std::string_view name) override;
  81   void open_object_section(std::string_view name) override;
  82   void close_section() override
  83   {
  84     ceph_assert(cursor != root);
  85     ceph_assert(!stack.empty());
  86     cursor = stack.top();
  87     stack.pop();
  88   }
  89   void dump_bool(std::string_view name, bool b) override;
  90   void dump_unsigned(std::string_view name, uint64_t u) override;
  91   void dump_int(std::string_view name, int64_t u) override;
  92   void dump_float(std::string_view name, double d) override;
  93   void dump_string(std::string_view name, std::string_view s) override;
  94   std::ostream& dump_stream(std::string_view name) override;
  95   void dump_format_va(std::string_view name, const char *ns, bool quoted, const char *fmt, va_list ap) override;
  96
  97   void flush(std::ostream& os) override
  98   {
  99       // This class is not a serializer: this doesn't make sense
 100       ceph_abort();
 101   }
 102
 103   int get_len() const override
 104   {
 105       // This class is not a serializer: this doesn't make sense
 106       ceph_abort();
 107       return 0;
 108   }
 109
 110   void write_raw_data(const char *data) override
 111   {
 112       // This class is not a serializer: this doesn't make sense
 113       ceph_abort();
 114   }
 115
 116   PyObject *get()
 117   {
 118     finish_pending_streams();
 119
 120     Py_INCREF(root);
 121     return root;
 122   }
 123
 124   void finish_pending_streams();
 125
 126 private:
 127   PyObject *root;
 128   PyObject *cursor;
 129   std::stack<PyObject *> stack;
 130
 131   void dump_pyobject(std::string_view name, PyObject *p);
 132
 133   class PendingStream {
 134     public:
 135     PyObject *cursor;
 136     std::string name;
 137     std::stringstream stream;
 138   };
 139
 140   std::list<std::shared_ptr<PendingStream> > pending_streams;
 141
 142 };
 143
 144 #endif
 145