| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | #include "../libnetdata.h" |
| 4 | #include "eval-internal.h" |
| 5 | |
| 6 | // ---------------------------------------------------------------------------- |
| 7 | // memory management |
| 8 | |
| 9 | EVAL_NODE *eval_node_alloc(int count) { |
| 10 | static int id = 1; |
| 11 | |
| 12 | EVAL_NODE *op = callocz(1, sizeof(EVAL_NODE) + (sizeof(EVAL_VALUE) * count)); |
| 13 | |
| 14 | op->id = id++; |
| 15 | op->operator = EVAL_OPERATOR_NOP; |
| 16 | op->precedence = 0; // Will be set based on the operator |
| 17 | op->count = count; |
| 18 | return op; |
| 19 | } |
| 20 | |
| 21 | void eval_node_set_value_to_node(EVAL_NODE *op, int pos, EVAL_NODE *value) { |
| 22 | if(pos >= op->count) |
| 23 | fatal("Invalid request to set position %d of OPERAND that has only %d values", pos + 1, op->count + 1); |
| 24 | |
| 25 | op->ops[pos].type = EVAL_VALUE_EXPRESSION; |
| 26 | op->ops[pos].expression = value; |
| 27 | } |
| 28 | |
| 29 | void eval_node_set_value_to_constant(EVAL_NODE *op, int pos, NETDATA_DOUBLE value) { |
| 30 | if(pos >= op->count) |
| 31 | fatal("Invalid request to set position %d of OPERAND that has only %d values", pos + 1, op->count + 1); |
| 32 | |
| 33 | op->ops[pos].type = EVAL_VALUE_NUMBER; |
| 34 | op->ops[pos].number = value; |
| 35 | } |
| 36 | |
| 37 | void eval_node_set_value_to_variable(EVAL_NODE *op, int pos, const char *variable) { |
| 38 | if(pos >= op->count) |
| 39 | fatal("Invalid request to set position %d of OPERAND that has only %d values", pos + 1, op->count + 1); |
| 40 | |
| 41 | op->ops[pos].type = EVAL_VALUE_VARIABLE; |
| 42 | op->ops[pos].variable = callocz(1, sizeof(EVAL_VARIABLE)); |
| 43 | op->ops[pos].variable->name = string_strdupz(variable); |
| 44 | } |
| 45 | |
| 46 | void eval_variable_free(EVAL_VARIABLE *v) { |
| 47 | string_freez(v->name); |
| 48 | freez(v); |
| 49 | } |
| 50 | |
| 51 | void eval_value_free(EVAL_VALUE *v) { |
| 52 | switch(v->type) { |
| 53 | case EVAL_VALUE_EXPRESSION: |
| 54 | eval_node_free(v->expression); |
| 55 | break; |
| 56 | |
| 57 | case EVAL_VALUE_VARIABLE: |
| 58 | eval_variable_free(v->variable); |
| 59 | break; |
| 60 | |
| 61 | default: |
| 62 | break; |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | void eval_node_free(EVAL_NODE *op) { |
| 67 | if(!op) return; |
| 68 | |
| 69 | if(op->count) { |
| 70 | int i; |
| 71 | for(i = op->count - 1; i >= 0 ;i--) |
| 72 | eval_value_free(&op->ops[i]); |
| 73 | } |
| 74 | |
| 75 | freez(op); |
| 76 | } |
| 77 | |
| 78 | // ---------------------------------------------------------------------------- |
| 79 | // parsed-as generation |
| 80 | |
| 81 | void print_parsed_as_variable(BUFFER *out, EVAL_VARIABLE *v, int *error __maybe_unused) { |
| 82 | buffer_sprintf(out, "${%s}", string2str(v->name)); |
| 83 | } |
| 84 | |
| 85 | void print_parsed_as_constant(BUFFER *out, NETDATA_DOUBLE n) { |
| 86 | if(unlikely(isnan(n))) { |
| 87 | buffer_strcat(out, "nan"); |
| 88 | return; |
| 89 | } |
| 90 | |
| 91 | if(unlikely(isinf(n))) { |
| 92 | buffer_strcat(out, "inf"); |
| 93 | return; |
| 94 | } |
| 95 | |
| 96 | char b[DOUBLE_MAX_LENGTH]; |
| 97 | print_netdata_double(b, n); |
| 98 | buffer_strcat(out, b); |
| 99 | } |
| 100 | |
| 101 | void print_parsed_as_value(BUFFER *out, EVAL_VALUE *v, int *error) { |
| 102 | switch(v->type) { |
| 103 | case EVAL_VALUE_EXPRESSION: |
| 104 | print_parsed_as_node(out, v->expression, error); |
| 105 | break; |
| 106 | |
| 107 | case EVAL_VALUE_NUMBER: |
| 108 | print_parsed_as_constant(out, v->number); |
| 109 | break; |
| 110 | |
| 111 | case EVAL_VALUE_VARIABLE: |
| 112 | print_parsed_as_variable(out, v->variable, error); |
| 113 | break; |
| 114 | |
| 115 | default: |
| 116 | *error = EVAL_ERROR_INVALID_VALUE; |
| 117 | break; |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | void print_parsed_as_node(BUFFER *out, EVAL_NODE *op, int *error) { |
| 122 | extern struct operator operators[]; |
| 123 | |
| 124 | if(unlikely(!op)) { |
| 125 | buffer_strcat(out, "NULL"); |
| 126 | *error = EVAL_ERROR_INVALID_VALUE; |
| 127 | return; |
| 128 | } |
| 129 | |
| 130 | if(unlikely(op->count != operators[op->operator].parameters)) { |
| 131 | buffer_sprintf(out, "INVALID PARAMETERS (operator requires %d, but node has %d)", operators[op->operator].parameters, op->count); |
| 132 | *error = EVAL_ERROR_INVALID_NUMBER_OF_OPERANDS; |
| 133 | return; |
| 134 | } |
| 135 | |
| 136 | if(operators[op->operator].isfunction) { |
| 137 | buffer_strcat(out, operators[op->operator].print_as); |
| 138 | buffer_strcat(out, "("); |
| 139 | print_parsed_as_value(out, &op->ops[0], error); |
| 140 | buffer_strcat(out, ")"); |
| 141 | return; |
| 142 | } |
| 143 | |
| 144 | if(op->operator == EVAL_OPERATOR_NOP) { |
| 145 | print_parsed_as_value(out, &op->ops[0], error); |
| 146 | return; |
| 147 | } |
| 148 | |
| 149 | if(op->operator == EVAL_OPERATOR_IF_THEN_ELSE) { |
| 150 | print_parsed_as_value(out, &op->ops[0], error); |
| 151 | buffer_strcat(out, " ? "); |
| 152 | print_parsed_as_value(out, &op->ops[1], error); |
| 153 | buffer_strcat(out, " : "); |
| 154 | print_parsed_as_value(out, &op->ops[2], error); |
| 155 | return; |
| 156 | } |
| 157 | |
| 158 | if(op->count == 1) { |
| 159 | buffer_strcat(out, operators[op->operator].print_as); |
| 160 | buffer_strcat(out, "("); |
| 161 | print_parsed_as_value(out, &op->ops[0], error); |
| 162 | buffer_strcat(out, ")"); |
| 163 | return; |
| 164 | } |
| 165 | |
| 166 | buffer_strcat(out, "("); |
| 167 | print_parsed_as_value(out, &op->ops[0], error); |
| 168 | buffer_strcat(out, " "); |
| 169 | buffer_strcat(out, operators[op->operator].print_as); |
| 170 | buffer_strcat(out, " "); |
| 171 | print_parsed_as_value(out, &op->ops[1], error); |
| 172 | buffer_strcat(out, ")"); |
| 173 | } |
| 174 | |
| 175 | // ---------------------------------------------------------------------------- |
| 176 | // public API utility functions |
| 177 | |
| 178 | const char *expression_strerror(int error) { |
| 179 | switch(error) { |
| 180 | case EVAL_ERROR_OK: |
| 181 | return "success"; |
| 182 | |
| 183 | case EVAL_ERROR_MISSING_CLOSE_SUBEXPRESSION: |
| 184 | return "missing closing parenthesis"; |
| 185 | |
| 186 | case EVAL_ERROR_UNKNOWN_OPERAND: |
| 187 | return "unknown operand"; |
| 188 | |
| 189 | case EVAL_ERROR_MISSING_OPERAND: |
| 190 | return "expected operand"; |
| 191 | |
| 192 | case EVAL_ERROR_MISSING_OPERATOR: |
| 193 | return "expected operator"; |
| 194 | |
| 195 | case EVAL_ERROR_REMAINING_GARBAGE: |
| 196 | return "remaining characters after expression"; |
| 197 | |
| 198 | case EVAL_ERROR_INVALID_VALUE: |
| 199 | return "invalid value structure - internal error"; |
| 200 | |
| 201 | case EVAL_ERROR_INVALID_NUMBER_OF_OPERANDS: |
| 202 | return "wrong number of operands for operation - internal error"; |
| 203 | |
| 204 | case EVAL_ERROR_VALUE_IS_NAN: |
| 205 | return "value is unset"; |
| 206 | |
| 207 | case EVAL_ERROR_VALUE_IS_INFINITE: |
| 208 | return "computed value is infinite"; |
| 209 | |
| 210 | case EVAL_ERROR_UNKNOWN_VARIABLE: |
| 211 | return "undefined variable"; |
| 212 | |
| 213 | case EVAL_ERROR_IF_THEN_ELSE_MISSING_ELSE: |
| 214 | return "missing second sub-expression of inline conditional"; |
| 215 | |
| 216 | default: |
| 217 | return "unknown error"; |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | const char *expression_source(EVAL_EXPRESSION *expression) { |
| 222 | if(!expression) |
| 223 | return string2str(NULL); |
| 224 | |
| 225 | return string2str(expression->source); |
| 226 | } |
| 227 | |
| 228 | const char *expression_parsed_as(EVAL_EXPRESSION *expression) { |
| 229 | if(!expression) |
| 230 | return string2str(NULL); |
| 231 | |
| 232 | return string2str(expression->parsed_as); |
| 233 | } |
| 234 | |
| 235 | const char *expression_error_msg(EVAL_EXPRESSION *expression) { |
| 236 | if(!expression || !expression->error_msg) |
| 237 | return ""; |
| 238 | |
| 239 | return buffer_tostring(expression->error_msg); |
| 240 | } |
| 241 | |
| 242 | NETDATA_DOUBLE expression_result(EVAL_EXPRESSION *expression) { |
| 243 | if(!expression) |
| 244 | return NAN; |
| 245 | |
| 246 | return expression->result; |
| 247 | } |
| 248 | |
| 249 | void expression_set_variable_lookup_callback(EVAL_EXPRESSION *expression, eval_expression_variable_lookup_t cb, void *data) { |
| 250 | if(!expression) |
| 251 | return; |
| 252 | |
| 253 | expression->variable_lookup_cb = cb; |
| 254 | expression->variable_lookup_cb_data = data; |
| 255 | } |
| 256 | |
| 257 | static size_t expression_hardcode_node_variable(EVAL_NODE *node, STRING *variable, NETDATA_DOUBLE value) { |
| 258 | size_t matches = 0; |
| 259 | |
| 260 | for(int i = 0; i < node->count; i++) { |
| 261 | switch(node->ops[i].type) { |
| 262 | case EVAL_VALUE_NUMBER: |
| 263 | case EVAL_VALUE_INVALID: |
| 264 | break; |
| 265 | |
| 266 | case EVAL_VALUE_VARIABLE: |
| 267 | if(node->ops[i].variable->name == variable) { |
| 268 | string_freez(node->ops[i].variable->name); |
| 269 | freez(node->ops[i].variable); |
| 270 | node->ops[i].type = EVAL_VALUE_NUMBER; |
| 271 | node->ops[i].number = value; |
| 272 | matches++; |
| 273 | } |
| 274 | break; |
| 275 | |
| 276 | case EVAL_VALUE_EXPRESSION: |
| 277 | matches += expression_hardcode_node_variable(node->ops[i].expression, variable, value); |
| 278 | break; |
| 279 | } |
| 280 | } |
| 281 | |
| 282 | return matches; |
| 283 | } |
| 284 | |
| 285 | static size_t str_replace_cpy(char *dst, size_t dst_size, |
| 286 | const char *src, |
| 287 | const char *variable, size_t variable_len, |
| 288 | const char *value, size_t value_len) { |
| 289 | |
| 290 | if (!dst || !src || !variable || !value || dst_size == 0 || variable_len == 0 || value_len == 0) |
| 291 | return 0; |
| 292 | |
| 293 | const char *pos = strstr(src, variable); |
| 294 | if (!pos) |
| 295 | return 0; |
| 296 | |
| 297 | size_t src_idx = 0; |
| 298 | size_t dst_idx = 0; |
| 299 | size_t matches = 0; |
| 300 | |
| 301 | while (src[src_idx] != '\0') { |
| 302 | if (pos && &src[src_idx] == pos) { |
| 303 | if (dst_idx + value_len >= dst_size) |
| 304 | return 0; |
| 305 | |
| 306 | matches++; |
| 307 | memcpy(&dst[dst_idx], value, value_len); |
| 308 | dst_idx += value_len; |
| 309 | src_idx += variable_len; |
| 310 | |
| 311 | pos = strstr(&src[src_idx], variable); |
| 312 | } else { |
| 313 | if (dst_idx + 1 >= dst_size) |
| 314 | return 0; |
| 315 | dst[dst_idx++] = src[src_idx++]; |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | if (dst_idx >= dst_size) |
| 320 | return 0; |
| 321 | |
| 322 | dst[dst_idx] = '\0'; |
| 323 | |
| 324 | return matches; |
| 325 | } |
| 326 | |
| 327 | |
| 328 | void expression_hardcode_variable(EVAL_EXPRESSION *expression, STRING *variable, NETDATA_DOUBLE value) { |
| 329 | if (!expression || !variable) |
| 330 | return; |
| 331 | |
| 332 | size_t matches = expression_hardcode_node_variable(expression->nodes, variable, value); |
| 333 | if (matches) { |
| 334 | char replace[DOUBLE_MAX_LENGTH]; |
| 335 | if(isnan(value)) |
| 336 | strncpyz(replace, "nan", sizeof(replace)); |
| 337 | else if(isinf(value)) |
| 338 | strncpyz(replace, "inf", sizeof(replace)); |
| 339 | else |
| 340 | print_netdata_double(replace, value); |
| 341 | size_t replace_len = strlen(replace); |
| 342 | |
| 343 | size_t source_len = string_strlen(expression->source); |
| 344 | |
| 345 | size_t find1_size = string_strlen(variable) + 1 + 1; |
| 346 | CLEAN_CHAR_P *find1 = mallocz(find1_size); |
| 347 | snprintfz(find1, find1_size, "$%s", string2str(variable)); |
| 348 | size_t find1_len = strlen(find1); |
| 349 | |
| 350 | size_t find2_size = string_strlen(variable) + 1 + 3; |
| 351 | CLEAN_CHAR_P *find2 = mallocz(find2_size); |
| 352 | snprintfz(find2, find2_size, "${%s}", string2str(variable)); |
| 353 | size_t find2_len = strlen(find2); |
| 354 | |
| 355 | // Calculate the maximum possible buffer size needed |
| 356 | // Source length + (max replacement length - min variable length) * matches + null terminator |
| 357 | size_t min_var_len = MIN(find1_len, find2_len); |
| 358 | size_t max_buf_size = source_len + 1 + (matches * (replace_len > min_var_len ? replace_len - min_var_len : 0)); |
| 359 | |
| 360 | CLEAN_CHAR_P *buf1 = mallocz(max_buf_size); |
| 361 | CLEAN_CHAR_P *buf2 = mallocz(max_buf_size); |
| 362 | |
| 363 | char *dst[2] = {buf1, buf2}; |
| 364 | |
| 365 | const char *src = string2str(expression->source); |
| 366 | size_t slot = 0; |
| 367 | while(matches) { |
| 368 | size_t matched = 0; |
| 369 | |
| 370 | matched = str_replace_cpy(dst[slot], max_buf_size, src, find1, find1_len, replace, replace_len); |
| 371 | if(matched) { |
| 372 | src = dst[slot]; |
| 373 | if(++slot > 1) slot = 0; |
| 374 | matches -= MIN(matches, matched); |
| 375 | } |
| 376 | |
| 377 | if(matches) { |
| 378 | matched = str_replace_cpy(dst[slot], max_buf_size, src, find2, find2_len, replace, replace_len); |
| 379 | if(matched) { |
| 380 | src = dst[slot]; |
| 381 | if (++slot > 1) slot = 0; |
| 382 | matches -= MIN(matches, matched); |
| 383 | } |
| 384 | } |
| 385 | } |
| 386 | |
| 387 | // Update the expression source with the new string. |
| 388 | string_freez(expression->source); |
| 389 | expression->source = string_strdupz(src); |
| 390 | } |
| 391 | } |