X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=src%2Fceph%2Fsrc%2Fdmclock%2Fsim%2Fsrc%2FConfUtils.cc;fp=src%2Fceph%2Fsrc%2Fdmclock%2Fsim%2Fsrc%2FConfUtils.cc;h=74ddb06ee290dee30abb39b10dda898d09894853;hb=812ff6ca9fcd3e629e49d4328905f33eee8ca3f5;hp=0000000000000000000000000000000000000000;hpb=15280273faafb77777eab341909a3f495cf248d9;p=stor4nfv.git

diff --git a/src/ceph/src/dmclock/sim/src/ConfUtils.cc b/src/ceph/src/dmclock/sim/src/ConfUtils.cc
new file mode 100644
index 0000000..74ddb06
--- /dev/null
+++ b/src/ceph/src/dmclock/sim/src/ConfUtils.cc
@@ -0,0 +1,574 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2011 New Dream Network
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#include <algorithm>
+#include <errno.h>
+#include <list>
+#include <map>
+#include <sstream>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <string>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <iostream>
+
+#include <assert.h>
+#include "ConfUtils.h"
+
+using std::cerr;
+using std::ostringstream;
+using std::pair;
+using std::string;
+
+#define MAX_CONFIG_FILE_SZ 0x40000000
+
+////////////////////////////// ConfLine //////////////////////////////
+ConfLine::
+ConfLine(const std::string &key_, const std::string val_,
+      const std::string newsection_, const std::string comment_, int line_no_)
+  : key(key_), val(val_), newsection(newsection_)
+{
+  // If you want to implement writable ConfFile support, you'll need to save
+  // the comment and line_no arguments here.
+}
+
+bool ConfLine::
+operator<(const ConfLine &rhs) const
+{
+  // We only compare keys.
+  // If you have more than one line with the same key in a given section, the
+  // last one wins.
+  if (key < rhs.key)
+    return true;
+  else
+    return false;
+}
+
+std::ostream &operator<<(std::ostream& oss, const ConfLine &l)
+{
+  oss << "ConfLine(key = '" << l.key << "', val='"
+      << l.val << "', newsection='" << l.newsection << "')";
+  return oss;
+}
+///////////////////////// ConfFile //////////////////////////
+ConfFile::
+ConfFile()
+{
+}
+
+ConfFile::
+~ConfFile()
+{
+}
+
+void ConfFile::
+clear()
+{
+  sections.clear();
+}
+
+/* We load the whole file into memory and then parse it.  Although this is not
+ * the optimal approach, it does mean that most of this code can be shared with
+ * the bufferlist loading function. Since bufferlists are always in-memory, the
+ * load_from_buffer interface works well for them.
+ * In general, configuration files should be a few kilobytes at maximum, so
+ * loading the whole configuration into memory shouldn't be a problem.
+ */
+int ConfFile::
+parse_file(const std::string &fname, std::deque<std::string> *errors,
+	   std::ostream *warnings)
+{
+  clear();
+
+  int ret = 0;
+  size_t sz;
+  char *buf = NULL;
+  char buf2[128];
+  FILE *fp = fopen(fname.c_str(), "r");
+  if (!fp) {
+    ret = -errno;
+    return ret;
+  }
+
+  struct stat st_buf;
+  if (fstat(fileno(fp), &st_buf)) {
+    ret = -errno;
+    ostringstream oss;
+    oss << "read_conf: failed to fstat '" << fname << "': " << strerror_r(ret, buf2, sizeof(buf2));
+    errors->push_back(oss.str());
+    goto done;
+  }
+
+  if (st_buf.st_size > MAX_CONFIG_FILE_SZ) {
+    ostringstream oss;
+    oss << "read_conf: config file '" << fname << "' is " << st_buf.st_size
+	<< " bytes, but the maximum is " << MAX_CONFIG_FILE_SZ;
+    errors->push_back(oss.str());
+    ret = -EINVAL;
+    goto done;
+  }
+
+  sz = (size_t)st_buf.st_size;
+  buf = (char*)malloc(sz);
+  if (!buf) {
+    ret = -ENOMEM;
+    goto done;
+  }
+
+  if (fread(buf, 1, sz, fp) != sz) {
+    if (ferror(fp)) {
+      ret = -errno;
+      ostringstream oss;
+      oss << "read_conf: fread error while reading '" << fname << "': "
+	  << strerror_r(ret, buf2, sizeof(buf2));
+      errors->push_back(oss.str());
+      goto done;
+    }
+    else {
+      ostringstream oss;
+      oss << "read_conf: unexpected EOF while reading '" << fname << "': "
+	  << "possible concurrent modification?";
+      errors->push_back(oss.str());
+      ret = -EIO;
+      goto done;
+    }
+  }
+
+  load_from_buffer(buf, sz, errors, warnings);
+  ret = 0;
+
+done:
+  free(buf);
+  fclose(fp);
+  return ret;
+}
+
+int ConfFile::
+read(const std::string &section, const std::string &key, std::string &val) const
+{
+  string k(normalize_key_name(key));
+
+  const_section_iter_t s = sections.find(section);
+  if (s == sections.end())
+    return -ENOENT;
+  ConfLine exemplar(k, "", "", "", 0);
+  ConfSection::const_line_iter_t l = s->second.lines.find(exemplar);
+  if (l == s->second.lines.end())
+    return -ENOENT;
+  val = l->val;
+  return 0;
+}
+
+ConfFile::const_section_iter_t ConfFile::
+sections_begin() const
+{
+  return sections.begin();
+}
+
+ConfFile::const_section_iter_t ConfFile::
+sections_end() const
+{
+  return sections.end();
+}
+
+void ConfFile::
+trim_whitespace(std::string &str, bool strip_internal)
+{
+  // strip preceding
+  const char *in = str.c_str();
+  while (true) {
+    char c = *in;
+    if ((!c) || (!isspace(c)))
+      break;
+    ++in;
+  }
+  char output[strlen(in) + 1];
+  strcpy(output, in);
+
+  // strip trailing
+  char *o = output + strlen(output);
+  while (true) {
+    if (o == output)
+      break;
+    --o;
+    if (!isspace(*o)) {
+      ++o;
+      *o = '\0';
+      break;
+    }
+  }
+
+  if (!strip_internal) {
+    str.assign(output);
+    return;
+  }
+
+  // strip internal
+  char output2[strlen(output) + 1];
+  char *out2 = output2;
+  bool prev_was_space = false;
+  for (char *u = output; *u; ++u) {
+    char c = *u;
+    if (isspace(c)) {
+      if (!prev_was_space)
+	*out2++ = c;
+      prev_was_space = true;
+    }
+    else {
+      *out2++ = c;
+      prev_was_space = false;
+    }
+  }
+  *out2++ = '\0';
+  str.assign(output2);
+}
+
+/* Normalize a key name.
+ *
+ * Normalized key names have no leading or trailing whitespace, and all
+ * whitespace is stored as underscores.  The main reason for selecting this
+ * normal form is so that in common/config.cc, we can use a macro to stringify
+ * the field names of md_config_t and get a key in normal form.
+ */
+std::string ConfFile::
+normalize_key_name(const std::string &key)
+{
+  string k(key);
+  ConfFile::trim_whitespace(k, true);
+  std::replace(k.begin(), k.end(), ' ', '_');
+  return k;
+}
+
+std::ostream &operator<<(std::ostream &oss, const ConfFile &cf)
+{
+  for (ConfFile::const_section_iter_t s = cf.sections_begin();
+       s != cf.sections_end(); ++s) {
+    oss << "[" << s->first << "]\n";
+    for (ConfSection::const_line_iter_t l = s->second.lines.begin();
+	 l != s->second.lines.end(); ++l) {
+      if (!l->key.empty()) {
+	oss << "\t" << l->key << " = \"" << l->val << "\"\n";
+      }
+    }
+  }
+  return oss;
+}
+
+void ConfFile::
+load_from_buffer(const char *buf, size_t sz, std::deque<std::string> *errors,
+		 std::ostream *warnings)
+{
+  errors->clear();
+
+  section_iter_t::value_type vt("global", ConfSection());
+  pair < section_iter_t, bool > vr(sections.insert(vt));
+  assert(vr.second);
+  section_iter_t cur_section = vr.first;
+  std::string acc;
+
+  const char *b = buf;
+  int line_no = 0;
+  size_t line_len = -1;
+  size_t rem = sz;
+  while (1) {
+    b += line_len + 1;
+    rem -= line_len + 1;
+    if (rem == 0)
+      break;
+    line_no++;
+
+    // look for the next newline
+    const char *end = (const char*)memchr(b, '\n', rem);
+    if (!end) {
+      ostringstream oss;
+      oss << "read_conf: ignoring line " << line_no << " because it doesn't "
+	  << "end with a newline! Please end the config file with a newline.";
+      errors->push_back(oss.str());
+      break;
+    }
+
+    // find length of line, and search for NULLs
+    line_len = 0;
+    bool found_null = false;
+    for (const char *tmp = b; tmp != end; ++tmp) {
+      line_len++;
+      if (*tmp == '\0') {
+	found_null = true;
+      }
+    }
+
+    if (found_null) {
+      ostringstream oss;
+      oss << "read_conf: ignoring line " << line_no << " because it has "
+	  << "an embedded null.";
+      errors->push_back(oss.str());
+      acc.clear();
+      continue;
+    }
+
+    if ((line_len >= 1) && (b[line_len-1] == '\\')) {
+      // A backslash at the end of a line serves as a line continuation marker.
+      // Combine the next line with this one.
+      // Remove the backslash itself from the text.
+      acc.append(b, line_len - 1);
+      continue;
+    }
+
+    acc.append(b, line_len);
+
+    //cerr << "acc = '" << acc << "'" << std::endl;
+    ConfLine *cline = process_line(line_no, acc.c_str(), errors);
+    acc.clear();
+    if (!cline)
+      continue;
+    const std::string &csection(cline->newsection);
+    if (!csection.empty()) {
+      std::map <std::string, ConfSection>::value_type nt(csection, ConfSection());
+      pair < section_iter_t, bool > nr(sections.insert(nt));
+      cur_section = nr.first;
+    }
+    else {
+      if (cur_section->second.lines.count(*cline)) {
+	// replace an existing key/line in this section, so that
+	//  [mysection]
+	//    foo = 1
+	//    foo = 2
+	// will result in foo = 2.
+	cur_section->second.lines.erase(*cline);
+	if (cline->key.length() && warnings)
+	  *warnings << "warning: line " << line_no << ": '" << cline->key << "' in section '"
+		    << cur_section->first << "' redefined " << std::endl;
+      }
+      // add line to current section
+      //std::cerr << "cur_section = " << cur_section->first << ", " << *cline << std::endl;
+      cur_section->second.lines.insert(*cline);
+    }
+    delete cline;
+  }
+
+  if (!acc.empty()) {
+    ostringstream oss;
+    oss << "read_conf: don't end with lines that end in backslashes!";
+    errors->push_back(oss.str());
+  }
+}
+
+/*
+ * A simple state-machine based parser.
+ * This probably could/should be rewritten with something like boost::spirit
+ * or yacc if the grammar ever gets more complex.
+ */
+ConfLine* ConfFile::
+process_line(int line_no, const char *line, std::deque<std::string> *errors)
+{
+  enum acceptor_state_t {
+    ACCEPT_INIT,
+    ACCEPT_SECTION_NAME,
+    ACCEPT_KEY,
+    ACCEPT_VAL_START,
+    ACCEPT_UNQUOTED_VAL,
+    ACCEPT_QUOTED_VAL,
+    ACCEPT_COMMENT_START,
+    ACCEPT_COMMENT_TEXT,
+  };
+  const char *l = line;
+  acceptor_state_t state = ACCEPT_INIT;
+  string key, val, newsection, comment;
+  bool escaping = false;
+  while (true) {
+    char c = *l++;
+    switch (state) {
+      case ACCEPT_INIT:
+	if (c == '\0')
+	  return NULL; // blank line. Not an error, but not interesting either.
+	else if (c == '[')
+	  state = ACCEPT_SECTION_NAME;
+	else if ((c == '#') || (c == ';'))
+	  state = ACCEPT_COMMENT_TEXT;
+	else if (c == ']') {
+	  ostringstream oss;
+	  oss << "unexpected right bracket at char " << (l - line)
+	      << ", line " << line_no;
+	  errors->push_back(oss.str());
+	  return NULL;
+	}
+	else if (isspace(c)) {
+	  // ignore whitespace here
+	}
+	else {
+	  // try to accept this character as a key
+	  state = ACCEPT_KEY;
+	  --l;
+	}
+	break;
+      case ACCEPT_SECTION_NAME:
+	if (c == '\0') {
+	  ostringstream oss;
+	  oss << "error parsing new section name: expected right bracket "
+	      << "at char " << (l - line) << ", line " << line_no;
+	  errors->push_back(oss.str());
+	  return NULL;
+	}
+	else if ((c == ']') && (!escaping)) {
+	  trim_whitespace(newsection, true);
+	  if (newsection.empty()) {
+	    ostringstream oss;
+	    oss << "error parsing new section name: no section name found? "
+	        << "at char " << (l - line) << ", line " << line_no;
+	    errors->push_back(oss.str());
+	    return NULL;
+	  }
+	  state = ACCEPT_COMMENT_START;
+	}
+	else if (((c == '#') || (c == ';')) && (!escaping)) {
+	  ostringstream oss;
+	  oss << "unexpected comment marker while parsing new section name, at "
+	      << "char " << (l - line) << ", line " << line_no;
+	  errors->push_back(oss.str());
+	  return NULL;
+	}
+	else if ((c == '\\') && (!escaping)) {
+	  escaping = true;
+	}
+	else {
+	  escaping = false;
+	  newsection += c;
+	}
+	break;
+      case ACCEPT_KEY:
+	if ((((c == '#') || (c == ';')) && (!escaping)) || (c == '\0')) {
+	  ostringstream oss;
+	  if (c == '\0') {
+	    oss << "end of key=val line " << line_no
+	        << " reached, no \"=val\" found...missing =?";
+	  } else {
+	    oss << "unexpected character while parsing putative key value, "
+		<< "at char " << (l - line) << ", line " << line_no;
+	  }
+	  errors->push_back(oss.str());
+	  return NULL;
+	}
+	else if ((c == '=') && (!escaping)) {
+	  key = normalize_key_name(key);
+	  if (key.empty()) {
+	    ostringstream oss;
+	    oss << "error parsing key name: no key name found? "
+	        << "at char " << (l - line) << ", line " << line_no;
+	    errors->push_back(oss.str());
+	    return NULL;
+	  }
+	  state = ACCEPT_VAL_START;
+	}
+	else if ((c == '\\') && (!escaping)) {
+	  escaping = true;
+	}
+	else {
+	  escaping = false;
+	  key += c;
+	}
+	break;
+      case ACCEPT_VAL_START:
+	if (c == '\0')
+	  return new ConfLine(key, val, newsection, comment, line_no);
+	else if ((c == '#') || (c == ';'))
+	  state = ACCEPT_COMMENT_TEXT;
+	else if (c == '"')
+	  state = ACCEPT_QUOTED_VAL;
+	else if (isspace(c)) {
+	  // ignore whitespace
+	}
+	else {
+	  // try to accept character as a val
+	  state = ACCEPT_UNQUOTED_VAL;
+	  --l;
+	}
+	break;
+      case ACCEPT_UNQUOTED_VAL:
+	if (c == '\0') {
+	  if (escaping) {
+	    ostringstream oss;
+	    oss << "error parsing value name: unterminated escape sequence "
+	        << "at char " << (l - line) << ", line " << line_no;
+	    errors->push_back(oss.str());
+	    return NULL;
+	  }
+	  trim_whitespace(val, false);
+	  return new ConfLine(key, val, newsection, comment, line_no);
+	}
+	else if (((c == '#') || (c == ';')) && (!escaping)) {
+	  trim_whitespace(val, false);
+	  state = ACCEPT_COMMENT_TEXT;
+	}
+	else if ((c == '\\') && (!escaping)) {
+	  escaping = true;
+	}
+	else {
+	  escaping = false;
+	  val += c;
+	}
+	break;
+      case ACCEPT_QUOTED_VAL:
+	if (c == '\0') {
+	  ostringstream oss;
+	  oss << "found opening quote for value, but not the closing quote. "
+	      << "line " << line_no;
+	  errors->push_back(oss.str());
+	  return NULL;
+	}
+	else if ((c == '"') && (!escaping)) {
+	  state = ACCEPT_COMMENT_START;
+	}
+	else if ((c == '\\') && (!escaping)) {
+	  escaping = true;
+	}
+	else {
+	  escaping = false;
+	  // Add anything, including whitespace.
+	  val += c;
+	}
+	break;
+      case ACCEPT_COMMENT_START:
+	if (c == '\0') {
+	  return new ConfLine(key, val, newsection, comment, line_no);
+	}
+	else if ((c == '#') || (c == ';')) {
+	  state = ACCEPT_COMMENT_TEXT;
+	}
+	else if (isspace(c)) {
+	  // ignore whitespace
+	}
+	else {
+	  ostringstream oss;
+	  oss << "unexpected character at char " << (l - line) << " of line "
+	      << line_no;
+	  errors->push_back(oss.str());
+	  return NULL;
+	}
+	break;
+      case ACCEPT_COMMENT_TEXT:
+	if (c == '\0')
+	  return new ConfLine(key, val, newsection, comment, line_no);
+	else
+	  comment += c;
+	break;
+      default:
+	assert(0);
+	break;
+    }
+    assert(c != '\0'); // We better not go past the end of the input string.
+  }
+}