diff options
Diffstat (limited to 'filter/f-inst.h')
-rw-r--r-- | filter/f-inst.h | 34 |
1 files changed, 1 insertions, 33 deletions
diff --git a/filter/f-inst.h b/filter/f-inst.h index 58a60f0f..33fcf4a9 100644 --- a/filter/f-inst.h +++ b/filter/f-inst.h @@ -7,39 +7,7 @@ * Can be freely distributed and used under the terms of the GNU GPL. * * Filter interpreter data structures and internal API. - * The filter code goes through several phases: - * - * 1 Parsing - * Flex- and Bison-generated parser decodes the human-readable data into - * a struct f_inst tree. This is an infix tree that was interpreted by - * depth-first search execution in previous versions of the interpreter. - * All instructions have their constructor: f_new_inst(FI_code, ...) - * translates into f_new_inst_FI_code(...) and the types are checked in - * compile time. - * - * 2 Linearize before interpreting - * The infix tree is always interpreted in the same order. Therefore we - * sort the instructions one after another into struct f_line. Results - * and arguments of these instructions are implicitly put on a value - * stack; e.g. the + operation just takes two arguments from the value - * stack and puts the result on there. - * - * 3 Interpret - * The given line is put on a custom execution stack. If needed (FI_CALL, - * FI_SWITCH, FI_AND, FI_OR, FI_CONDITION, ...), another line is put on top - * of the stack; when that line finishes, the execution continues on the - * older lines on the stack where it stopped before. - * - * 4 Same - * On config reload, the filters have to be compared whether channel - * reload is needed or not. The comparison is done by comparing the - * struct f_line's recursively. - * - * The main purpose of this rework was to improve filter performance - * by making the interpreter non-recursive. - * - * The other outcome is concentration of instruction definitions to - * one place -- filter/f-inst.c + * See filter/f-inst.c for documentation. */ #ifndef _BIRD_F_INST_H_ |