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
|
/* Copyright (C) 2007-2011 G.P. Halkes
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License version 3, as
published by the Free Software Foundation.
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, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include "definitions.h"
#include "util.h"
#include "option.h"
#include "buffer.h"
typedef enum {
PRINTING_CHANGED,
PRINTING_AFTER_CONTEXT,
PRE_BUFFERING,
BUFFERING,
/* The initial states are only used at the start of printing, to prevent
printing of the separator string (--) before the first block of output. */
PRE_BUFFERING_INITIAL,
BUFFERING_INITIAL
} PrintState;
static CharBuffer *contextBuffers;
static PrintState state = PRE_BUFFERING_INITIAL;
static int bufferIndex;
static int afterContextLines;
/** Initialize the context buffers. */
void initContextBuffers(void) {
int i;
errno = 0;
contextBuffers = (CharBuffer *) safe_malloc((option.contextLines + 1) * sizeof(CharBuffer));
for (i = 0; i <= option.contextLines; i++)
VECTOR_INIT(contextBuffers[i]);
}
/** Write a character, buffering if necessary.
@param c The character to write.
@param common Boolean to indicate whether the character belongs to both
the old and the new file.
*/
void addchar(char c, bool common) {
/* Using ignore variable to shut up gcc about the warn_unused_result attribute set on fwrite. */
int i, ignore;
if (!option.context) {
putc(c, option.output);
return;
}
/* Check whether we have buffered output that we need to print because of
encountering a non-common character. */
if (!common) {
switch (state) {
case PRINTING_CHANGED:
case PRINTING_AFTER_CONTEXT:
break;
/* If we have entered a regular buffering state, all buffers are in use.
However, the set of buffers is used as a ring buffer so first print all
buffers after the current one, then print all buffers before the current. */
case BUFFERING:
ignore = fwrite("--\n", 1, 3, option.output);
/* FALLTHROUGH */
case BUFFERING_INITIAL:
for (i = bufferIndex + 1; i <= option.contextLines; i++)
ignore = fwrite(contextBuffers[i].data, 1, contextBuffers[i].used, option.output);
/* FALLTHROUGH */
/* In pre-buffering state, only the first buffers are used. Once we start
wrapping around, we change state to a regular buffering state. */
case PRE_BUFFERING:
case PRE_BUFFERING_INITIAL:
for (i = 0; i <= bufferIndex; i++)
ignore = fwrite(contextBuffers[i].data, 1, contextBuffers[i].used, option.output);
break;
default:
PANIC();
}
state = PRINTING_CHANGED;
}
/* Decided whether to buffer or print the character. */
switch (state) {
case BUFFERING:
case PRE_BUFFERING:
case BUFFERING_INITIAL:
case PRE_BUFFERING_INITIAL:
VECTOR_APPEND(contextBuffers[bufferIndex], c);
break;
case PRINTING_AFTER_CONTEXT:
case PRINTING_CHANGED:
putc(c, option.output);
break;
default:
PANIC();
}
if (c == '\n') {
switch (state) {
case PRINTING_CHANGED:
if (option.contextLines == 0) {
state = PRE_BUFFERING;
break;
}
state = PRINTING_AFTER_CONTEXT;
afterContextLines = 0;
break;
case PRINTING_AFTER_CONTEXT:
afterContextLines++;
if (afterContextLines == option.contextLines) {
state = PRE_BUFFERING;
bufferIndex = 0;
}
break;
case PRE_BUFFERING_INITIAL:
case PRE_BUFFERING:
bufferIndex++;
/* Once we have filled all buffers, we change to a regular buffering state. */
if (bufferIndex > option.contextLines) {
state = state == PRE_BUFFERING ? BUFFERING : BUFFERING_INITIAL;
bufferIndex = 0;
}
break;
case BUFFERING_INITIAL:
case BUFFERING:
bufferIndex++;
if (bufferIndex > option.contextLines)
bufferIndex = 0;
break;
default:
PANIC();
}
/* We just saw a newline, so we have either entered a buffering state,
or already were in one, and finished filling the old buffer. The new
buffer must be filled from the start. */
contextBuffers[bufferIndex].used = 0;
}
}
/* Macro to ensure we use the same format and arguments for printing the line
number information in all print statements. */
#define LINENUMBERS_FMT_ARGS "%*d:%-*d ", option.lineNumbers, oldLineNumber, option.lineNumbers, newLineNumber
/** Print line number information, buffering if necessary.
@param oldLineNumber The line number in the old file.
@param newLineNumber The line number in the new file.
*/
void printLineNumbers(int oldLineNumber, int newLineNumber) {
int printed, allowed;
if (!option.context) {
printf(LINENUMBERS_FMT_ARGS);
return;
}
switch (state) {
case BUFFERING:
case PRE_BUFFERING:
case BUFFERING_INITIAL:
case PRE_BUFFERING_INITIAL:
allowed = contextBuffers[bufferIndex].allocated - contextBuffers[bufferIndex].used;
/* SUSv2 specification of snprintf does not handle zero sized buffers nicely :-(
Therefore, we have to ensure that there is at least room for one byte, but as
we will be printing 2 numbers and a colon and a space, we might as well ask for
4 bytes. */
VECTOR_ALLOCATE(contextBuffers[bufferIndex], 4);
printed = snprintf(contextBuffers[bufferIndex].data + contextBuffers[bufferIndex].used, allowed, LINENUMBERS_FMT_ARGS);
/* If there was not enough room to hold all the bytes for the line numbers,
resize the buffer and try again. */
if (printed > allowed) {
VECTOR_ALLOCATE(contextBuffers[bufferIndex], printed);
allowed = contextBuffers[bufferIndex].allocated - contextBuffers[bufferIndex].used;
printed = snprintf(contextBuffers[bufferIndex].data + contextBuffers[bufferIndex].used, allowed, LINENUMBERS_FMT_ARGS);
}
/* Sanity check: the number of characters printed should be at least 2
[probably 4, but I don't know all possible number systems]. */
ASSERT(printed >= 2);
contextBuffers[bufferIndex].used += printed;
break;
case PRINTING_AFTER_CONTEXT:
case PRINTING_CHANGED:
printf(LINENUMBERS_FMT_ARGS);
break;
default:
PANIC();
}
}
/** Print a string, buffering if necessary.
@param string The string to print.
@param bytes The length of the string.
The string should not contain newline characters.
*/
void writeString(const char *string, size_t bytes) {
/* Using ignore variable to shut up gcc about the warn_unused_result attribute set on fwrite. */
int ignore;
if (!option.context) {
ignore = fwrite(string, 1, bytes, option.output);
return;
}
switch (state) {
case BUFFERING:
case PRE_BUFFERING:
case BUFFERING_INITIAL:
case PRE_BUFFERING_INITIAL:
VECTOR_ALLOCATE(contextBuffers[bufferIndex], bytes);
memcpy(contextBuffers[bufferIndex].data + contextBuffers[bufferIndex].used, string, bytes);
contextBuffers[bufferIndex].used += bytes;
break;
case PRINTING_AFTER_CONTEXT:
case PRINTING_CHANGED:
ignore = fwrite(string, 1, bytes, option.output);
break;
default:
PANIC();
}
}
|