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Diffstat (limited to 'libio/parsestream.cc')
| -rw-r--r-- | libio/parsestream.cc | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/libio/parsestream.cc b/libio/parsestream.cc new file mode 100644 index 00000000000..320afd06d9b --- /dev/null +++ b/libio/parsestream.cc @@ -0,0 +1,317 @@ +/* This is part of libio/iostream, providing -*- C++ -*- input/output. +Copyright (C) 1993 Free Software Foundation + +This file is part of the GNU IO Library. This library 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; either version 2, or (at your option) +any later version. + +This library 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 library; see the file COPYING. If not, write to the Free +Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +As a special exception, if you link this library with files +compiled with a GNU compiler to produce an executable, this does not cause +the resulting executable to be covered by the GNU General Public License. +This exception does not however invalidate any other reasons why +the executable file might be covered by the GNU General Public License. + +Written by Per Bothner (bothner@cygnus.com). */ + +#ifdef __GNUG__ +#pragma implementation +#endif +#include "libioP.h" +#include "parsestream.h" +#include <stdlib.h> + +streambuf* parsebuf::setbuf(char*, int) +{ + return NULL; +} + +int parsebuf::tell_in_line() +{ + return 0; +} + +int parsebuf::pbackfail(int c) +{ + if (c == EOF) + return 0; + if (seekoff(-1, ios::cur) == EOF) + return EOF; + return (unsigned char)c; +} + +char* parsebuf::current_line() { return NULL; } + +streampos parsebuf::seekoff(streamoff offset, _seek_dir dir, int) +{ + // Make offset relative to line start. + switch (dir) { + case ios::beg: + offset -= pos_at_line_start; + break; + case ios::cur: + offset += tell_in_line(); + break; + default: + return EOF; + } + if (offset < -1) + return EOF; + if (offset > _line_length + 1) + return EOF; + return seek_in_line(offset) + pos_at_line_start; +} + +// string_parsebuf invariants: +// The reserve ares (base() .. ebuf()) is always the entire string. +// The get area (eback() .. egptr()) is the extended current line +// (i.e. with the '\n' at either end, if these exist). + +string_parsebuf::string_parsebuf(char *buf, int len, + int delete_at_close /* = 0*/) +: parsebuf() +{ + setb(buf, buf+len, delete_at_close); + register char *ptr = buf; + while (ptr < ebuf() && *ptr != '\n') ptr++; + _line_length = ptr - buf; + setg(buf, buf, ptr); +} + +int string_parsebuf::underflow() +{ + register char* ptr = egptr(); // Point to end of current_line + do { + int i = right() - ptr; + if (i <= 0) + return EOF; + ptr++; i--; // Skip '\n'. + char *line_start = ptr; + while (ptr < right() && *ptr == '\n') ptr++; + setg(line_start-1, line_start, ptr + (ptr < right())); + pos_at_line_start = line_start - left(); + _line_length = ptr - line_start; + __line_number++; + } while (gptr() == ptr); + return *gptr(); +} + +char* string_parsebuf::current_line() +{ + char *ptr = eback(); + if (__line_number > 0) + ptr++; // Skip '\n' at end of previous line. + return ptr; +} + +int string_parsebuf::tell_in_line() +{ + int offset = gptr() - eback(); + if (__line_number > 0) + offset--; + return offset; +} + +int string_parsebuf::seek_in_line(int i) +{ + int delta = i - tell_in_line(); + gbump(delta); // FIXME: Needs error (bounds) checking! + return i; +} + +static const char NewLine[1] = { '\n' }; + +general_parsebuf::general_parsebuf(streambuf *buf, int delete_arg_buf) + : parsebuf() +{ + delete_buf = delete_arg_buf; + sbuf = buf; + int buf_size = 128; + char* buffer = ALLOC_BUF(buf_size); + setb(buffer, buffer+buf_size, 1); +// setg(buffer, buffer, buffer); +} + +general_parsebuf::~general_parsebuf() +{ + if (delete_buf) + delete sbuf; +} + +int general_parsebuf::underflow() +{ + register char *ptr = base(); + int has_newline = eback() < gptr() && gptr()[-1] == '\n'; + if (has_newline) + *ptr++ = '\n'; + register streambuf *sb = sbuf; + register int ch; + for (;;) { + ch = sb->sbumpc(); + if (ch == EOF) + break; + if (ptr == ebuf()) { + int old_size = ebuf() - base(); + char *new_buffer = new char[old_size * 2]; + memcpy(new_buffer, base(), old_size); + setb(new_buffer, new_buffer + 2 * old_size, 1); + ptr = new_buffer + old_size; + } + *ptr++ = ch; + if (ch == '\n') + break; + } + char *cur_pos = base() + has_newline; + pos_at_line_start += _line_length + 1; + _line_length = ptr - cur_pos; + if (ch != EOF || _line_length > 0) + __line_number++; + setg(base(), cur_pos, ptr); + return ptr == cur_pos ? EOF : cur_pos[0]; +} + +char* general_parsebuf::current_line() +{ + char* ret = base(); + if (__line_number > 1) + ret++; // Move past '\n' from end of previous line. + return ret; +} + +int general_parsebuf::tell_in_line() +{ + int off = gptr() - base(); + if (__line_number > 1) + off--; // Subtract 1 for '\n' from end of previous line. + return off; +} + +int general_parsebuf::seek_in_line(int i) +{ + if (__line_number == 0) + (void)general_parsebuf::underflow(); + if (__line_number > 1) + i++; // Add 1 for '\n' from end of previous line. + if (i < 0) i = 0; + int len = egptr() - eback(); + if (i > len) i = len; + setg(base(), base() + i, egptr()); + return i; +} + +func_parsebuf::func_parsebuf(CharReader func, void *argm) : parsebuf() +{ + read_func = func; + arg = argm; + buf_start = NULL; + buf_end = NULL; + setb((char*)NewLine, (char*)NewLine+1, 0); + setg((char*)NewLine, (char*)NewLine+1, (char*)NewLine+1); + backed_up_to_newline = 0; +} + +int func_parsebuf::tell_in_line() +{ + if (buf_start == NULL) + return 0; + if (egptr() != (char*)NewLine+1) + // Get buffer was line buffer. + return gptr() - buf_start; + if (backed_up_to_newline) + return -1; // Get buffer is '\n' preceding current line. + // Get buffer is '\n' following current line. + return (buf_end - buf_start) + (gptr() - (char*)NewLine); +} + +char* func_parsebuf::current_line() +{ + return buf_start; +} + +int func_parsebuf::seek_in_line(int i) +{ + if (i < 0) { + // Back up to preceding '\n'. + if (i < -1) i = -1; + backed_up_to_newline = 1; + setg((char*)NewLine, (char*)NewLine+(i+1), (char*)NewLine+1); + return i; + } + backed_up_to_newline = 0; + int line_length = buf_end-buf_start; + if (i <= line_length) { + setg(buf_start, buf_start+i, buf_end); + return i; + } + i -= line_length; + if (i > 0) i = 1; + setg((char*)NewLine, (char*)NewLine+i, (char*)NewLine+1); + return line_length + i; +} + +int func_parsebuf::underflow() +{ + retry: + if (gptr() < egptr()) + return *gptr(); + if (gptr() != (char*)NewLine+1) { + // Get buffer was line buffer. Move to following '\n'. + setg((char*)NewLine, (char*)NewLine, (char*)NewLine+1); + return *gptr(); + } + if (backed_up_to_newline) + // Get buffer was '\n' preceding current line. Move to current line. + backed_up_to_newline = 0; + else { + // Get buffer was '\n' following current line. Read new line. + if (buf_start) free(buf_start); + char *str = (*read_func)(arg); + buf_start = str; + if (str == NULL) + return EOF; + // Initially, _line_length == -1, so pos_at_line_start becomes 0. + pos_at_line_start += _line_length + 1; + _line_length = strlen(str); + buf_end = str + _line_length; + __line_number++; + } + setg(buf_start, buf_start, buf_end); + goto retry; +} + +#if 0 +size_t parsebuf::line_length() +{ + if (current_line_length == (size_t)(-1)) // Initial value; + (void)sgetc(); + return current_line_length; +} +#endif + +int parsebuf::seek_in_line(int i) +{ +#if 1 + abort(); + return i; // Suppress warnings. +#else + if (i > 0) { + size_t len = line_length(); + if ((unsigned)i > len) i = len; + } + else if (i < -1) i = -1; + int new_pos = seekoff(pos_at_line_start + i, ios::beg); + if (new_pos == EOF) + return tell_in_line(); + else return new_pos - pos_at_line_start; +#endif +} |