typelib.cc

/* Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

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   which is part of C Driver for MySQL (Connector/C), is also subject to the
   Universal FOSS Exception, version 1.0, a copy of which can be found at
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   This program is distributed in the hope that it will be useful,
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

/**
  @file mysys/typelib.cc
  Functions to handle typelib
*/

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>

#include "m_ctype.h"
#include "m_string.h"
#include "my_alloc.h"
#include "my_dbug.h"
#include "my_inttypes.h"
#include "my_macros.h"
#include "my_sys.h"
#include "typelib.h"

#define is_field_separator(X) ((X) == ',' || (X) == '=')

int find_type_or_exit(const char *x, TYPELIB *typelib, const char *option) {
  int res;
  const char **ptr;

  if ((res = find_type((char *)x, typelib, FIND_TYPE_BASIC)) <= 0) {
    ptr = typelib->type_names;
    if (!*x)
      fprintf(stderr, "No option given to %s\n", option);
    else
      fprintf(stderr, "Unknown option to %s: %s\n", option, x);
    fprintf(stderr, "Alternatives are: '%s'", *ptr);
    while (*++ptr) fprintf(stderr, ",'%s'", *ptr);
    fprintf(stderr, "\n");
    exit(1);
  }
  return res;
}

/**
  Search after a string in a list of strings. Endspace in x is not compared.

  @param x              String to find
  @param typelib        TYPELIB (struct of pointer to values + count)
  @param flags          flags to tune behaviour: a combination of
                        FIND_TYPE_NO_PREFIX
                        FIND_TYPE_ALLOW_NUMBER
                        FIND_TYPE_COMMA_TERM.
                        FIND_TYPE_NO_OVERWRITE can be passed but is
                        superfluous (is always implicitely on).

  @retval
    -1  Too many matching values
  @retval
    0   No matching value
  @retval
    >0  Offset+1 in typelib for matched string
*/

int find_type(const char *x, const TYPELIB *typelib, uint flags) {
  int find, pos;
  int findpos = 0; /* guarded by find */
  const char *i;
  const char *j;
  DBUG_ENTER("find_type");
  DBUG_PRINT("enter", ("x: '%s'  lib: %p", x, typelib));

  DBUG_ASSERT(!(flags & ~(FIND_TYPE_NO_PREFIX | FIND_TYPE_ALLOW_NUMBER |
                          FIND_TYPE_NO_OVERWRITE | FIND_TYPE_COMMA_TERM)));
  if (!typelib->count) {
    DBUG_PRINT("exit", ("no count"));
    DBUG_RETURN(0);
  }
  find = 0;
  for (pos = 0; (j = typelib->type_names[pos]); pos++) {
    for (i = x;
         *i && (!(flags & FIND_TYPE_COMMA_TERM) || !is_field_separator(*i)) &&
         my_toupper(&my_charset_latin1, *i) ==
             my_toupper(&my_charset_latin1, *j);
         i++, j++)
      ;
    if (!*j) {
      while (*i == ' ') i++; /* skip_end_space */
      if (!*i || ((flags & FIND_TYPE_COMMA_TERM) && is_field_separator(*i)))
        DBUG_RETURN(pos + 1);
    }
    if ((!*i && (!(flags & FIND_TYPE_COMMA_TERM) || !is_field_separator(*i))) &&
        (!*j || !(flags & FIND_TYPE_NO_PREFIX))) {
      find++;
      findpos = pos;
    }
  }
  if (find == 0 && (flags & FIND_TYPE_ALLOW_NUMBER) && x[0] == '#' &&
      strend(x)[-1] == '#' && (findpos = atoi(x + 1) - 1) >= 0 &&
      (uint)findpos < typelib->count)
    find = 1;
  else if (find == 0 || !x[0]) {
    DBUG_PRINT("exit", ("Couldn't find type"));
    DBUG_RETURN(0);
  } else if (find != 1 || (flags & FIND_TYPE_NO_PREFIX)) {
    DBUG_PRINT("exit", ("Too many possybilities"));
    DBUG_RETURN(-1);
  }
  DBUG_RETURN(findpos + 1);
} /* find_type */

/**
  Get name of type nr

  @note
  first type is 1, 0 = empty field
*/

void make_type(char *to, uint nr, TYPELIB *typelib) {
  DBUG_ENTER("make_type");
  if (!nr)
    to[0] = 0;
  else
    (void)my_stpcpy(to, get_type(typelib, nr - 1));
  DBUG_VOID_RETURN;
} /* make_type */

/**
  Get type

  @note
  first type is 0
*/

const char *get_type(TYPELIB *typelib, uint nr) {
  if (nr < (uint)typelib->count && typelib->type_names)
    return (typelib->type_names[nr]);
  return "?";
}

/**
  Create an integer value to represent the supplied comma-seperated
  string where each string in the TYPELIB denotes a bit position.

  @param x      string to decompose
  @param lib    TYPELIB (struct of pointer to values + count)
  @param err    index (not char position) of string element which was not
                found or 0 if there was no error

  @retval
    a integer representation of the supplied string
*/

my_ulonglong find_typeset(char *x, TYPELIB *lib, int *err) {
  my_ulonglong result;
  int find;
  char *i;
  DBUG_ENTER("find_set");
  DBUG_PRINT("enter", ("x: '%s'  lib: %p", x, lib));

  if (!lib->count) {
    DBUG_PRINT("exit", ("no count"));
    DBUG_RETURN(0);
  }
  result = 0;
  *err = 0;
  while (*x) {
    (*err)++;
    i = x;
    while (*x && !is_field_separator(*x)) x++;
    if (x[0] && x[1]) /* skip separator if found */
      x++;
    if ((find = find_type(i, lib, FIND_TYPE_COMMA_TERM) - 1) < 0)
      DBUG_RETURN(0);
    result |= (1ULL << find);
  }
  *err = 0;
  DBUG_RETURN(result);
} /* find_set */

/**
  Create a copy of a specified TYPELIB structure.

  @param root   pointer to a MEM_ROOT object for allocations
  @param from   pointer to a source TYPELIB structure

  @retval
    pointer to the new TYPELIB structure on successful copy
  @retval
    NULL otherwise
*/

TYPELIB *copy_typelib(MEM_ROOT *root, TYPELIB *from) {
  TYPELIB *to;
  uint i;

  if (!from) return NULL;

  if (!(to = (TYPELIB *)alloc_root(root, sizeof(TYPELIB)))) return NULL;

  if (!(to->type_names = (const char **)alloc_root(
            root, (sizeof(char *) + sizeof(int)) * (from->count + 1))))
    return NULL;
  to->type_lengths = (unsigned int *)(to->type_names + from->count + 1);
  to->count = from->count;
  if (from->name) {
    if (!(to->name = strdup_root(root, from->name))) return NULL;
  } else
    to->name = NULL;

  for (i = 0; i < from->count; i++) {
    if (!(to->type_names[i] =
              strmake_root(root, from->type_names[i], from->type_lengths[i])))
      return NULL;
    to->type_lengths[i] = from->type_lengths[i];
  }
  to->type_names[to->count] = NULL;
  to->type_lengths[to->count] = 0;

  return to;
}

static const char *on_off_default_names[] = {"off", "on", "default", 0};
static TYPELIB on_off_default_typelib = {
    array_elements(on_off_default_names) - 1, "", on_off_default_names, 0};

/**
  Parse a TYPELIB name from the buffer

  @param lib          Set of names to scan for.
  @param strpos INOUT Start of the buffer (updated to point to the next
                      character after the name)
  @param end          End of the buffer

  @note
  The buffer is assumed to contain one of the names specified in the TYPELIB,
  followed by comma, '=', or end of the buffer.

  @retval
    0   No matching name
  @retval
    >0  Offset+1 in typelib for matched name
*/

static uint parse_name(const TYPELIB *lib, const char **strpos,
                       const char *end) {
  const char *pos = *strpos;
  uint find = find_type(pos, lib, FIND_TYPE_COMMA_TERM);
  for (; pos != end && *pos != '=' && *pos != ','; pos++)
    ;
  *strpos = pos;
  return find;
}

/**
  Parse and apply a set of flag assingments

  @param lib               Flag names
  @param default_name      Number of "default" in the typelib
  @param cur_set           Current set of flags (start from this state)
  @param default_set       Default set of flags (use this for assign-default
                           keyword and flag=default assignments)
  @param str               String to be parsed
  @param length            Length of the string
  @param err_pos      OUT  If error, set to point to start of wrong set string
                           NULL on success
  @param err_len      OUT  If error, set to the length of wrong set string

  @details
  Parse a set of flag assignments, that is, parse a string in form:

    param_name1=value1,param_name2=value2,...

  where the names are specified in the TYPELIB, and each value can be
  either 'on','off', or 'default'. Setting the same name twice is not
  allowed.

  Besides param=val assignments, we support the "default" keyword (keyword
  default_name in the typelib). It can be used one time, if specified it
  causes us to build the new set over the default_set rather than cur_set
  value.

  @note
  it's not charset aware

  @retval
    Parsed set value if (*errpos == NULL), otherwise undefined
*/

my_ulonglong find_set_from_flags(const TYPELIB *lib, size_t default_name,
                                 my_ulonglong cur_set, my_ulonglong default_set,
                                 const char *str, uint length, char **err_pos,
                                 uint *err_len) {
  const char *end = str + length;
  my_ulonglong flags_to_set = 0, flags_to_clear = 0, res;
  bool set_defaults = 0;

  *err_pos = 0; /* No error yet */
  if (str != end) {
    const char *start = str;
    for (;;) {
      const char *pos = start;
      uint flag_no, value;

      if (!(flag_no = parse_name(lib, &pos, end))) goto err;

      if (flag_no == default_name) {
        /* Using 'default' twice isn't allowed. */
        if (set_defaults) goto err;
        set_defaults = true;
      } else {
        my_ulonglong bit = (1ULL << (flag_no - 1));
        /* parse the '=on|off|default' */
        if ((flags_to_clear | flags_to_set) & bit || pos >= end ||
            *pos++ != '=' ||
            !(value = parse_name(&on_off_default_typelib, &pos, end)))
          goto err;

        if (value == 1) /* this is '=off' */
          flags_to_clear |= bit;
        else if (value == 2) /* this is '=on' */
          flags_to_set |= bit;
        else /* this is '=default'  */
        {
          if (default_set & bit)
            flags_to_set |= bit;
          else
            flags_to_clear |= bit;
        }
      }
      if (pos >= end) break;

      if (*pos++ != ',') goto err;

      start = pos;
      continue;
    err:
      *err_pos = (char *)start;
      *err_len = (uint)(end - start);
      break;
    }
  }
  res = set_defaults ? default_set : cur_set;
  res |= flags_to_set;
  res &= ~flags_to_clear;
  return res;
}