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428
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1 /* Generic stream implementation -- header file.
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2 Copyright (C) 1995 Free Software Foundation, Inc.
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3 Copyright (C) 1996 Ben Wing.
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4
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5 This file is part of XEmacs.
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6
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7 XEmacs is free software; you can redistribute it and/or modify it
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8 under the terms of the GNU General Public License as published by the
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9 Free Software Foundation; either version 2, or (at your option) any
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10 later version.
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11
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12 XEmacs is distributed in the hope that it will be useful, but WITHOUT
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13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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15 for more details.
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16
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17 You should have received a copy of the GNU General Public License
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18 along with XEmacs; see the file COPYING. If not, write to
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19 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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20 Boston, MA 02111-1307, USA. */
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21
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22 /* Synched up with: Not in FSF. */
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23
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24 /* Written by Ben Wing. */
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25
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440
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26 #ifndef INCLUDED_lstream_h_
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27 #define INCLUDED_lstream_h_
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428
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28
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29 /************************************************************************/
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30 /* definition of Lstream object */
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31 /************************************************************************/
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32
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33 DECLARE_LRECORD (lstream, struct lstream);
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34 #define XLSTREAM(x) XRECORD (x, lstream, struct lstream)
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35 #define XSETLSTREAM(x, p) XSETRECORD (x, p, lstream)
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36 #define LSTREAMP(x) RECORDP (x, lstream)
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37 /* #define CHECK_LSTREAM(x) CHECK_RECORD (x, lstream)
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38 Lstream pointers should never escape to the Lisp level, so
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39 functions should not be doing this. */
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40
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41 #ifndef EOF
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42 #define EOF (-1)
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43 #endif
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44
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45 typedef enum lstream_buffering
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46 {
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47 /* No buffering. */
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48 LSTREAM_UNBUFFERED,
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49 /* Buffer until a '\n' character is reached. */
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50 LSTREAM_LINE_BUFFERED,
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51 /* Buffer in standard-size (i.e. 512-byte) blocks. */
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52 LSTREAM_BLOCK_BUFFERED,
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53 /* Buffer in blocks of a specified size. */
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54 LSTREAM_BLOCKN_BUFFERED,
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55 /* Buffer until the stream is closed (only applies to write-only
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56 streams). Only one call to the stream writer will be made,
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57 and that is when the stream is closed. */
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58 LSTREAM_UNLIMITED
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59 } Lstream_buffering;
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60
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61 /* Methods defining how this stream works. Some may be undefined. */
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62
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63 /* We do not implement the seek/tell paradigm. I tried to do that,
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64 but getting the semantics right in the presence of buffering is
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65 extremely tricky and very error-prone and basically not worth it.
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66 This is especially the case with complicated streams like
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67 decoding streams -- the seek pointer in this case can't be a single
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68 integer but has to be a whole complicated structure that records
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69 all of the stream's state at the time.
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70
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71 Rewind semantics are generally easy to implement, so we do provide
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72 a rewind method. Even rewind() may not be available on a stream,
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73 however -- e.g. on process output. */
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74
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75 typedef struct lstream_implementation
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76 {
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442
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77 const char *name;
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428
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78 size_t size; /* Number of additional bytes to be allocated with this
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79 stream. Access this data using Lstream_data(). */
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80 /* Read some data from the stream's end and store it into DATA, which
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81 can hold SIZE bytes. Return the number of bytes read. A return
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82 value of 0 means no bytes can be read at this time. This may
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83 be because of an EOF, or because there is a granularity greater
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84 than one byte that the stream imposes on the returned data, and
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85 SIZE is less than this granularity. (This will happen frequently
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86 for streams that need to return whole characters, because
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87 Lstream_read() calls the reader function repeatedly until it
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88 has the number of bytes it wants or until 0 is returned.)
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89 The lstream functions do not treat a 0 return as EOF or do
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90 anything special; however, the calling function will interpret
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91 any 0 it gets back as EOF. This will normally not happen unless
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92 the caller calls Lstream_read() with a very small size.
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93
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94 This function can be NULL if the stream is output-only. */
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442
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95 /* The omniscient mly, blinded by the irresistible thrall of Common
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428
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96 Lisp, thinks that it is bogus that the types and implementations
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97 of input and output streams are the same. */
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98 ssize_t (*reader) (Lstream *stream, unsigned char *data, size_t size);
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99 /* Send some data to the stream's end. Data to be sent is in DATA
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100 and is SIZE bytes. Return the number of bytes sent. This
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101 function can send and return fewer bytes than is passed in; in
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102 that case, the function will just be called again until there is
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103 no data left or 0 is returned. A return value of 0 means that no
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104 more data can be currently stored, but there is no error; the
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105 data will be squirrelled away until the writer can accept
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106 data. (This is useful, e.g., of you're dealing with a
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107 non-blocking file descriptor and are getting EWOULDBLOCK errors.)
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108 This function can be NULL if the stream is input-only. */
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442
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109 ssize_t (*writer) (Lstream *stream, const unsigned char *data, size_t size);
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428
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110 /* Return non-zero if the last write operation on the stream resulted
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111 in an attempt to block (EWOULDBLOCK). If this method does not
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112 exists, the implementation returns 0 */
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113 int (*was_blocked_p) (Lstream *stream);
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114 /* Rewind the stream. If this is NULL, the stream is not seekable. */
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115 int (*rewinder) (Lstream *stream);
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116 /* Indicate whether this stream is seekable -- i.e. it can be rewound.
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117 This method is ignored if the stream does not have a rewind
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118 method. If this method is not present, the result is determined
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119 by whether a rewind method is present. */
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120 int (*seekable_p) (Lstream *stream);
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121 /* Perform any additional operations necessary to flush the
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122 data in this stream. */
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123 int (*flusher) (Lstream *stream);
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124 /* Perform any additional operations necessary to close this
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125 stream down. May be NULL. This function is called when
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126 Lstream_close() is called or when the stream is garbage-
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127 collected. When this function is called, all pending data
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128 in the stream will already have been written out. */
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129 int (*closer) (Lstream *stream);
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130 /* Mark this object for garbage collection. Same semantics as
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131 a standard Lisp_Object marker. This function can be NULL. */
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132 Lisp_Object (*marker) (Lisp_Object lstream);
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133 } Lstream_implementation;
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134
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135 #define DEFINE_LSTREAM_IMPLEMENTATION(name,c_name,size) \
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136 Lstream_implementation c_name[1] = \
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137 { { (name), (size) } }
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138
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139 #define LSTREAM_FL_IS_OPEN 1
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140 #define LSTREAM_FL_READ 2
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141 #define LSTREAM_FL_WRITE 4
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142 #define LSTREAM_FL_NO_PARTIAL_CHARS 8
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143 #define LSTREAM_FL_CLOSE_AT_DISKSAVE 16
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144
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145 struct lstream
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146 {
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147 struct lcrecord_header header;
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442
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148 const Lstream_implementation *imp; /* methods for this stream */
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428
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149 Lstream_buffering buffering; /* type of buffering in use */
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150 size_t buffering_size; /* number of bytes buffered */
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151
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152 unsigned char *in_buffer; /* holds characters read from stream end */
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153 size_t in_buffer_size; /* allocated size of buffer */
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154 size_t in_buffer_current; /* number of characters in buffer */
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155 size_t in_buffer_ind; /* pointer to next character to take from buffer */
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156
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157 unsigned char *out_buffer; /* holds characters to write to stream end */
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158 size_t out_buffer_size; /* allocated size of buffer */
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159 size_t out_buffer_ind; /* pointer to next buffer spot to write a character */
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160
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161 /* The unget buffer is more or less a stack -- things get pushed
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162 onto the end and read back from the end. Lstream_read()
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163 basically reads backwards from the end to get stuff; Lstream_unread()
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164 similarly has to push the data on backwards. */
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165 unsigned char *unget_buffer; /* holds characters pushed back onto input */
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166 size_t unget_buffer_size; /* allocated size of buffer */
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167 size_t unget_buffer_ind; /* pointer to next buffer spot to write a character */
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168
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169 size_t byte_count;
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170 long flags; /* Align pointer for 64 bit machines (kny) */
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171 char data[1];
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172 };
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173
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174 #define LSTREAM_TYPE_P(lstr, type) \
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175 ((lstr)->imp == lstream_##type)
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176
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177 #ifdef ERROR_CHECK_TYPECHECK
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442
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178 INLINE_HEADER struct lstream *
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428
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179 error_check_lstream_type (struct lstream *stream,
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442
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180 const Lstream_implementation *imp);
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181 INLINE_HEADER struct lstream *
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428
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182 error_check_lstream_type (struct lstream *stream,
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442
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183 const Lstream_implementation *imp)
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428
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184 {
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185 assert (stream->imp == imp);
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186 return stream;
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187 }
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188 # define LSTREAM_TYPE_DATA(lstr, type) \
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189 ((struct type##_stream *) \
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190 Lstream_data (error_check_lstream_type(lstr, lstream_##type)))
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191 #else
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192 # define LSTREAM_TYPE_DATA(lstr, type) \
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193 ((struct type##_stream *) Lstream_data (lstr))
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194 #endif
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195
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196 /* Declare that lstream-type TYPE has method M; used in
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197 initialization routines */
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198 #define LSTREAM_HAS_METHOD(type, m) \
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199 (lstream_##type->m = type##_##m)
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200
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201
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442
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202 Lstream *Lstream_new (const Lstream_implementation *imp,
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203 const char *mode);
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428
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204 void Lstream_reopen (Lstream *lstr);
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205 void Lstream_set_buffering (Lstream *lstr, Lstream_buffering buffering,
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206 int buffering_size);
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207 int Lstream_flush (Lstream *lstr);
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208 int Lstream_flush_out (Lstream *lstr);
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209 int Lstream_fputc (Lstream *lstr, int c);
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210 int Lstream_fgetc (Lstream *lstr);
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211 void Lstream_fungetc (Lstream *lstr, int c);
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212 ssize_t Lstream_read (Lstream *lstr, void *data, size_t size);
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442
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213 ssize_t Lstream_write (Lstream *lstr, const void *data, size_t size);
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428
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214 int Lstream_was_blocked_p (Lstream *lstr);
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442
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215 void Lstream_unread (Lstream *lstr, const void *data, size_t size);
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428
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216 int Lstream_rewind (Lstream *lstr);
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217 int Lstream_seekable_p (Lstream *lstr);
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218 int Lstream_close (Lstream *lstr);
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219 void Lstream_delete (Lstream *lstr);
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220 void Lstream_set_character_mode (Lstream *str);
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221
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222 /* Call the function equivalent if the out buffer is full. Otherwise,
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223 add to the end of the out buffer and, if line buffering is called for
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224 and the character marks the end of a line, write out the buffer. */
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225
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226 #define Lstream_putc(stream, c) \
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227 ((stream)->out_buffer_ind >= (stream)->out_buffer_size ? \
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228 Lstream_fputc (stream, c) : \
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229 ((stream)->out_buffer[(stream)->out_buffer_ind++] = \
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230 (unsigned char) (c), \
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231 (stream)->byte_count++, \
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232 (stream)->buffering == LSTREAM_LINE_BUFFERED && \
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233 (stream)->out_buffer[(stream)->out_buffer_ind - 1] == '\n' ? \
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234 Lstream_flush_out (stream) : 0))
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235
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236 /* Retrieve from unget buffer if there are any characters there;
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237 else retrieve from in buffer if there's anything there;
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238 else call the function equivalent */
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239 #define Lstream_getc(stream) \
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240 ((stream)->unget_buffer_ind > 0 ? \
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241 ((stream)->byte_count++, \
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242 (stream)->unget_buffer[--(stream)->unget_buffer_ind]) : \
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243 (stream)->in_buffer_ind < (stream)->in_buffer_current ? \
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244 ((stream)->byte_count++, \
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245 (stream)->in_buffer[(stream)->in_buffer_ind++]) : \
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246 Lstream_fgetc (stream))
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247
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248 /* Add to the end if it won't overflow buffer; otherwise call the
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249 function equivalent */
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250 #define Lstream_ungetc(stream, c) \
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251 ((stream)->unget_buffer_ind >= (stream)->unget_buffer_size ? \
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252 Lstream_fungetc (stream, c) : \
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253 (void) ((stream)->byte_count--, \
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254 ((stream)->unget_buffer[(stream)->unget_buffer_ind++] = \
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255 (unsigned char) (c))))
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256
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257 #define Lstream_data(stream) ((void *) ((stream)->data))
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258 #define Lstream_byte_count(stream) ((stream)->byte_count)
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259
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260
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261 /************************************************************************/
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262 /* working with an Lstream as a stream of Emchars */
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263 /************************************************************************/
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264
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265 #ifdef MULE
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266
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267 #ifndef BYTE_ASCII_P
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268 #include "mule-charset.h"
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269 #endif
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270
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442
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271 INLINE_HEADER Emchar Lstream_get_emchar (Lstream *stream);
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272 INLINE_HEADER Emchar
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428
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273 Lstream_get_emchar (Lstream *stream)
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274 {
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275 int c = Lstream_getc (stream);
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444
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276 return (c < 0x80 /* c == EOF || BYTE_ASCII_P (c) */
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277 ? (Emchar) c
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278 : Lstream_get_emchar_1 (stream, c));
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428
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279 }
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280
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442
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281 INLINE_HEADER int Lstream_put_emchar (Lstream *stream, Emchar ch);
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282 INLINE_HEADER int
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428
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283 Lstream_put_emchar (Lstream *stream, Emchar ch)
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284 {
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285 return CHAR_ASCII_P (ch) ?
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286 Lstream_putc (stream, ch) :
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287 Lstream_fput_emchar (stream, ch);
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288 }
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289
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442
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290 INLINE_HEADER void Lstream_unget_emchar (Lstream *stream, Emchar ch);
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291 INLINE_HEADER void
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428
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292 Lstream_unget_emchar (Lstream *stream, Emchar ch)
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293 {
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294 if (CHAR_ASCII_P (ch))
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295 Lstream_ungetc (stream, ch);
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296 else
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297 Lstream_funget_emchar (stream, ch);
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298 }
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299 #else /* not MULE */
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300
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301 # define Lstream_get_emchar(stream) Lstream_getc (stream)
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302 # define Lstream_put_emchar(stream, ch) Lstream_putc (stream, ch)
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303 # define Lstream_unget_emchar(stream, ch) Lstream_ungetc (stream, ch)
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304
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305 #endif /* not MULE */
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306
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307
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308 /************************************************************************/
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309 /* Lstream implementations */
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310 /************************************************************************/
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311
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312 /* Flags we can pass to the filedesc and stdio streams. */
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313
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314 /* If set, close the descriptor or FILE * when the stream is closed. */
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315 #define LSTR_CLOSING 1
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316
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317 /* If set, allow quitting out of the actual I/O. */
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318 #define LSTR_ALLOW_QUIT 2
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319
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320 /* If set and filedesc_stream_set_pty_flushing() has been called
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321 on the stream, do not send more than pty_max_bytes on a single
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322 line without flushing the data out using the eof_char. */
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323 #define LSTR_PTY_FLUSHING 4
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324
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325 /* If set, an EWOULDBLOCK error is not treated as an error but
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326 simply causes the write function to return 0 as the number
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327 of bytes written out. */
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328 #define LSTR_BLOCKED_OK 8
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329
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330 Lisp_Object make_stdio_input_stream (FILE *stream, int flags);
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331 Lisp_Object make_stdio_output_stream (FILE *stream, int flags);
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332 Lisp_Object make_filedesc_input_stream (int filedesc, int offset, int count,
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333 int flags);
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334 Lisp_Object make_filedesc_output_stream (int filedesc, int offset, int count,
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335 int flags);
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336 void filedesc_stream_set_pty_flushing (Lstream *stream,
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337 int pty_max_bytes,
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338 Bufbyte eof_char);
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339 int filedesc_stream_fd (Lstream *stream);
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340 Lisp_Object make_lisp_string_input_stream (Lisp_Object string,
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341 Bytecount offset,
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342 Bytecount len);
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442
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343 Lisp_Object make_fixed_buffer_input_stream (const void *buf, size_t size);
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440
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344 Lisp_Object make_fixed_buffer_output_stream (void *buf, size_t size);
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442
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345 const unsigned char *fixed_buffer_input_stream_ptr (Lstream *stream);
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428
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346 unsigned char *fixed_buffer_output_stream_ptr (Lstream *stream);
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347 Lisp_Object make_resizing_buffer_output_stream (void);
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348 unsigned char *resizing_buffer_stream_ptr (Lstream *stream);
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349 Lisp_Object make_dynarr_output_stream (unsigned_char_dynarr *dyn);
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350 #define LSTR_SELECTIVE 1
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351 #define LSTR_IGNORE_ACCESSIBLE 2
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352 Lisp_Object make_lisp_buffer_input_stream (struct buffer *buf, Bufpos start,
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353 Bufpos end, int flags);
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354 Lisp_Object make_lisp_buffer_output_stream (struct buffer *buf, Bufpos pos,
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|
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355 int flags);
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356 Bufpos lisp_buffer_stream_startpos (Lstream *stream);
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357
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440
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358 #endif /* INCLUDED_lstream_h_ */
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