summaryrefslogtreecommitdiff
path: root/client/readline.cc
blob: b6643b86356c02a863872c33b0c3c04c26ca17a8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
/*
   Copyright (c) 2000, 2011, Oracle and/or its affiliates.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License 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
*/

/* readline for batch mode */

#include <my_global.h>
#include <my_sys.h>
#include <m_string.h>
#include <my_dir.h>
#include "my_readline.h"

static bool init_line_buffer(LINE_BUFFER *buffer,File file,ulong size,
			    ulong max_size);
static bool init_line_buffer_from_string(LINE_BUFFER *buffer,char * str);
static size_t fill_buffer(LINE_BUFFER *buffer);
static char *intern_read_line(LINE_BUFFER *buffer, ulong *out_length);


LINE_BUFFER *batch_readline_init(ulong max_size,FILE *file)
{
  LINE_BUFFER *line_buff;

#ifndef __WIN__
  MY_STAT input_file_stat;
  if (my_fstat(fileno(file), &input_file_stat, MYF(MY_WME)) ||
      MY_S_ISDIR(input_file_stat.st_mode) ||
      MY_S_ISBLK(input_file_stat.st_mode))
    return 0;
#endif

  if (!(line_buff=(LINE_BUFFER*)
        my_malloc(sizeof(*line_buff),MYF(MY_WME | MY_ZEROFILL))))
    return 0;
  if (init_line_buffer(line_buff,my_fileno(file),IO_SIZE,max_size))
  {
    my_free(line_buff);
    return 0;
  }
  return line_buff;
}


char *batch_readline(LINE_BUFFER *line_buff, bool binary_mode)
{
  char *pos;
  ulong out_length;
  LINT_INIT(out_length);

  if (!(pos=intern_read_line(line_buff, &out_length)))
    return 0;
  if (out_length && pos[out_length-1] == '\n')
  {
    /*
      On Windows platforms we also need to remove '\r', unconditionally.  On
      Unix-like platforms we only remove it if we are not on binary mode.
     */

    /* Remove '\n' */
    if (--out_length && IF_WIN(1,!binary_mode) && pos[out_length-1] == '\r')
      /* Remove '\r' */
      out_length--;                                 
  }
  line_buff->read_length=out_length;
  pos[out_length]=0;
  return pos;
}


void batch_readline_end(LINE_BUFFER *line_buff)
{
  if (line_buff)
  {
    my_free(line_buff->buffer);
    my_free(line_buff);
  }
}


LINE_BUFFER *batch_readline_command(LINE_BUFFER *line_buff, char * str)
{
  if (!line_buff)
    if (!(line_buff=(LINE_BUFFER*)
          my_malloc(sizeof(*line_buff),MYF(MY_WME | MY_ZEROFILL))))
      return 0;
  if (init_line_buffer_from_string(line_buff,str))
  {
    my_free(line_buff);
    return 0;
  }
  return line_buff;
}


/*****************************************************************************
      Functions to handle buffered readings of lines from a stream
******************************************************************************/

static bool
init_line_buffer(LINE_BUFFER *buffer,File file,ulong size,ulong max_buffer)
{
  buffer->file=file;
  buffer->bufread=size;
  buffer->max_size=max_buffer;
  if (!(buffer->buffer = (char*) my_malloc(buffer->bufread+1,
					   MYF(MY_WME | MY_FAE))))
    return 1;
  buffer->end_of_line=buffer->end=buffer->buffer;
  buffer->buffer[0]=0;				/* For easy start test */
  return 0;
}

/*
  init_line_buffer_from_string can be called on the same buffer
  several times. the resulting buffer will contain a
  concatenation of all strings separated by spaces
*/
static bool init_line_buffer_from_string(LINE_BUFFER *buffer,char * str)
{
  uint old_length=(uint)(buffer->end - buffer->buffer);
  uint length= (uint) strlen(str);
  if (!(buffer->buffer= buffer->start_of_line= buffer->end_of_line=
	(char*) my_realloc((uchar*) buffer->buffer, old_length+length+2,
                           MYF(MY_FAE|MY_ALLOW_ZERO_PTR))))
    return 1;
  buffer->end= buffer->buffer + old_length;
  if (old_length)
    buffer->end[-1]=' ';
  memcpy(buffer->end, str, length);
  buffer->end[length]= '\n';
  buffer->end[length+1]= 0;
  buffer->end+= length+1;
  buffer->eof=1;
  buffer->max_size=1;
  return 0;
}


/*
  Fill the buffer retaining the last n bytes at the beginning of the
  newly filled buffer (for backward context).	Returns the number of new
  bytes read from disk.
*/

static size_t fill_buffer(LINE_BUFFER *buffer)
{
  size_t read_count;
  uint bufbytes= (uint) (buffer->end - buffer->start_of_line);

  if (buffer->eof)
    return 0;					/* Everything read */

  /* See if we need to grow the buffer. */

  for (;;)
  {
    uint start_offset=(uint) (buffer->start_of_line - buffer->buffer);
    read_count=(buffer->bufread - bufbytes)/IO_SIZE;
    if ((read_count*=IO_SIZE))
      break;
    if (buffer->bufread * 2 > buffer->max_size)
    {
      /*
        So we must grow the buffer but we cannot due to the max_size limit.
        Return 0 w/o setting buffer->eof to signal this condition.
      */
      return 0;
    }
    buffer->bufread *= 2;
    if (!(buffer->buffer = (char*) my_realloc(buffer->buffer,
					      buffer->bufread+1,
					      MYF(MY_WME | MY_FAE))))
    {
      buffer->error= my_errno;
      return (size_t) -1;
    }
    buffer->start_of_line=buffer->buffer+start_offset;
    buffer->end=buffer->buffer+bufbytes;
  }

  /* Shift stuff down. */
  if (buffer->start_of_line != buffer->buffer)
  {
    bmove(buffer->buffer,buffer->start_of_line,(uint) bufbytes);
    buffer->end=buffer->buffer+bufbytes;
  }

  /* Read in new stuff. */
  if ((read_count= my_read(buffer->file, (uchar*) buffer->end, read_count,
			   MYF(MY_WME))) == MY_FILE_ERROR)
  {
    buffer->error= my_errno;
    return (size_t) -1;
  }

  DBUG_PRINT("fill_buff", ("Got %lu bytes", (ulong) read_count));

  if (!read_count)
  {
    buffer->eof = 1;
    /* Kludge to pretend every nonempty file ends with a newline. */
    if (bufbytes && buffer->end[-1] != '\n')
    {
      read_count = 1;
      *buffer->end = '\n';
    }
  }
  buffer->end_of_line=(buffer->start_of_line=buffer->buffer)+bufbytes;
  buffer->end+=read_count;
  *buffer->end=0;				/* Sentinel */
  return read_count;
}


char *intern_read_line(LINE_BUFFER *buffer, ulong *out_length)
{
  char *pos;
  size_t length;
  DBUG_ENTER("intern_read_line");

  buffer->start_of_line=buffer->end_of_line;
  for (;;)
  {
    pos=buffer->end_of_line;
    while (*pos != '\n' && pos != buffer->end)
      pos++;
    if (pos == buffer->end)
    {
      /*
        fill_buffer() can return NULL on EOF (in which case we abort),
        on error, or when the internal buffer has hit the size limit.
        In the latter case return what we have read so far and signal
        string truncation.
      */
      if (!(length= fill_buffer(buffer)))
      {
        if (buffer->eof)
          DBUG_RETURN(0);
      }
      else if (length == (size_t) -1)
        DBUG_RETURN(NULL);
      else
        continue;
      pos--;					/* break line here */
      buffer->truncated= 1;
    }
    else
      buffer->truncated= 0;
    buffer->end_of_line=pos+1;
    *out_length=(ulong) (pos + 1 - buffer->eof - buffer->start_of_line);
    DBUG_RETURN(buffer->start_of_line);
  }
}