| 1 | /* This file is part of the Linux Trace Toolkit viewer |
| 2 | * Copyright (C) 2003-2004 Michel Dagenais |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License Version 2 as |
| 6 | * published by the Free Software Foundation; |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License |
| 14 | * along with this program; if not, write to the Free Software |
| 15 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 16 | * MA 02111-1307, USA. |
| 17 | */ |
| 18 | |
| 19 | /* |
| 20 | consist in AND, OR and NOT nested expressions, forming a tree with |
| 21 | simple relations as leaves. The simple relations test is a field |
| 22 | in an event is equal, not equal, smaller, smaller or equal, larger, or |
| 23 | larger or equal to a specified value. */ |
| 24 | |
| 25 | #include <lttv/filter.h> |
| 26 | |
| 27 | /* |
| 28 | read_token |
| 29 | |
| 30 | read_expression |
| 31 | ( read expr ) |
| 32 | simple expr [ op expr ] |
| 33 | |
| 34 | read_simple_expression |
| 35 | read_field_path [ rel value ] |
| 36 | |
| 37 | read_field_path |
| 38 | read_field_component [. field path] |
| 39 | |
| 40 | read_field_component |
| 41 | name [ \[ value \] ] |
| 42 | |
| 43 | data struct: |
| 44 | and/or(left/right) |
| 45 | not(child) |
| 46 | op(left/right) |
| 47 | path(component...) -> field |
| 48 | */ |
| 49 | |
| 50 | /** |
| 51 | * Add an filtering option to the current tree |
| 52 | * @param expression Current expression to parse |
| 53 | * @return success/failure of operation |
| 54 | */ |
| 55 | gboolean |
| 56 | parse_simple_expression(GString* expression) { |
| 57 | |
| 58 | unsigned i; |
| 59 | |
| 60 | // for(i=0;i<strlen(expression);i++) { |
| 61 | // |
| 62 | // } |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * Creates a new lttv_filter |
| 67 | * @param expression filtering options string |
| 68 | * @param t pointer to the current LttvTrace |
| 69 | * @return the current lttv_filter or NULL if error |
| 70 | */ |
| 71 | lttv_filter* |
| 72 | lttv_filter_new(char *expression, LttvTrace *t) { |
| 73 | |
| 74 | unsigned |
| 75 | i, |
| 76 | p=0, /* parenthesis nesting value */ |
| 77 | b=0; /* current breakpoint in expression string */ |
| 78 | |
| 79 | gpointer tree; |
| 80 | |
| 81 | GString *current_option = g_string_new(""); |
| 82 | lttv_simple_expression current_expression; |
| 83 | |
| 84 | g_print("filter::lttv_filter_new()\n"); /* debug */ |
| 85 | |
| 86 | /* |
| 87 | * 1. parse expression |
| 88 | * 2. construct binary tree |
| 89 | * 3. return corresponding filter |
| 90 | */ |
| 91 | |
| 92 | /* |
| 93 | * Binary tree memory allocation |
| 94 | * - based upon a preliminary block size |
| 95 | */ |
| 96 | gulong size = (strlen(expression)/6) * 1.5; |
| 97 | tree = g_malloc(size*sizeof(lttv_filter_tree)); |
| 98 | |
| 99 | /* |
| 100 | * Parse entire expression and construct |
| 101 | * the binary tree. There are two steps |
| 102 | * in browsing that string |
| 103 | * 1. finding boolean ops ( &,|,^,! ) and parenthesis |
| 104 | * 2. finding simple expressions |
| 105 | * - field path |
| 106 | * - op ( >, <, =, >=, <=, !=) |
| 107 | * - value |
| 108 | */ |
| 109 | |
| 110 | for(i=0;i<strlen(expression);i++) { |
| 111 | switch(expression[i]) { |
| 112 | /* |
| 113 | * boolean operators |
| 114 | */ |
| 115 | case '&': /* and */ |
| 116 | parse_simple_expression(current_option); |
| 117 | g_print("%s\n",¤t_option); |
| 118 | current_option = g_string_new(""); |
| 119 | break; |
| 120 | case '|': /* or */ |
| 121 | g_print("%s\n",current_option); |
| 122 | current_option = g_string_new(""); |
| 123 | break; |
| 124 | case '^': /* xor */ |
| 125 | g_print("%s\n",current_option); |
| 126 | current_option = g_string_new(""); |
| 127 | break; |
| 128 | case '!': /* not, or not equal (math op) */ |
| 129 | if(expression[i+1] == '=') { /* != */ |
| 130 | current_expression.op = LTTV_FIELD_NE; |
| 131 | i++; |
| 132 | } else { /* ! */ |
| 133 | g_print("%s\n",current_option); |
| 134 | current_option = g_string_new(""); |
| 135 | } |
| 136 | break; |
| 137 | case '(': /* start of parenthesis */ |
| 138 | p++; |
| 139 | break; |
| 140 | case ')': /* end of parenthesis */ |
| 141 | p--; |
| 142 | break; |
| 143 | |
| 144 | /* |
| 145 | * mathematic operators |
| 146 | */ |
| 147 | case '<': /* lower, lower or equal */ |
| 148 | if(expression[i+1] == '=') { /* <= */ |
| 149 | i++; |
| 150 | current_expression.op = LTTV_FIELD_LE; |
| 151 | } else current_expression.op = LTTV_FIELD_LT; |
| 152 | break; |
| 153 | case '>': /* higher, higher or equal */ |
| 154 | if(expression[i+1] == '=') { /* >= */ |
| 155 | i++; |
| 156 | current_expression.op = LTTV_FIELD_GE; |
| 157 | } else current_expression.op = LTTV_FIELD_GT; |
| 158 | break; |
| 159 | case '=': /* equal */ |
| 160 | current_expression.op = LTTV_FIELD_EQ; |
| 161 | break; |
| 162 | default: /* concatening current string */ |
| 163 | g_string_append_c(current_option,expression[i]); |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | if( p>0 ) { |
| 168 | g_warning("Wrong filtering options, the string\n\"%s\"\n\ |
| 169 | is not valid due to parenthesis incorrect use",expression); |
| 170 | return NULL; |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | /** |
| 175 | * Apply the filter to a specific trace |
| 176 | * @param filter the current filter applied |
| 177 | * @param tracefile the trace to apply the filter to |
| 178 | * @return success/failure of operation |
| 179 | */ |
| 180 | gboolean |
| 181 | lttv_filter_tracefile(lttv_filter *filter, void *tracefile) { |
| 182 | |
| 183 | } |
| 184 | |
| 185 | /** |
| 186 | * Apply the filter to a specific event |
| 187 | * @param filter the current filter applied |
| 188 | * @param event the event to apply the filter to |
| 189 | * @return success/failure of operation |
| 190 | */ |
| 191 | gboolean |
| 192 | lttv_filter_event(lttv_filter *filter, void *event) { |
| 193 | |
| 194 | } |