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80 lines
2.4 KiB
C
80 lines
2.4 KiB
C
#include <stdio.h>
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#include "lib/mlrutil.h"
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#include "containers/sllv.h"
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#include "mapping/mappers.h"
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typedef struct _mapper_tac_state_t {
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sllv_t* records;
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} mapper_tac_state_t;
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static void mapper_tac_usage(FILE* o, char* argv0, char* verb);
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static mapper_t* mapper_tac_parse_cli(int* pargi, int argc, char** argv,
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cli_reader_opts_t* _, cli_writer_opts_t* __);
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static mapper_t* mapper_tac_alloc();
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static void mapper_tac_free(mapper_t* pmapper, context_t* _);
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static sllv_t* mapper_tac_process(lrec_t* pinrec, context_t* pctx, void* pvstate);
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// ----------------------------------------------------------------
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mapper_setup_t mapper_tac_setup = {
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.verb = "tac",
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.pusage_func = mapper_tac_usage,
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.pparse_func = mapper_tac_parse_cli,
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.ignores_input = FALSE,
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};
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// ----------------------------------------------------------------
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static void mapper_tac_usage(FILE* o, char* argv0, char* verb) {
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fprintf(o, "Usage: %s %s\n", argv0, verb);
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fprintf(o, "Prints records in reverse order from the order in which they were encountered.\n");
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}
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static mapper_t* mapper_tac_parse_cli(int* pargi, int argc, char** argv,
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cli_reader_opts_t* _, cli_writer_opts_t* __)
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{
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if ((argc - *pargi) < 1) {
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mapper_tac_usage(stderr, argv[0], argv[*pargi]);
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return NULL;
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}
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mapper_t* pmapper = mapper_tac_alloc();
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*pargi += 1;
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return pmapper;
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}
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// ----------------------------------------------------------------
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static mapper_t* mapper_tac_alloc() {
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mapper_t* pmapper = mlr_malloc_or_die(sizeof(mapper_t));
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mapper_tac_state_t* pstate = mlr_malloc_or_die(sizeof(mapper_tac_state_t));
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pstate->records = sllv_alloc();
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pmapper->pvstate = pstate;
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pmapper->pprocess_func = mapper_tac_process;
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pmapper->pfree_func = mapper_tac_free;
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return pmapper;
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}
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static void mapper_tac_free(mapper_t* pmapper, context_t* _) {
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mapper_tac_state_t* pstate = pmapper->pvstate;
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// Free the container
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sllv_free(pstate->records);
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free(pstate);
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free(pmapper);
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}
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// ----------------------------------------------------------------
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static sllv_t* mapper_tac_process(lrec_t* pinrec, context_t* pctx, void* pvstate) {
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mapper_tac_state_t* pstate = pvstate;
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if (pinrec != NULL) {
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// The caller will free the outrecs
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sllv_append(pstate->records, pinrec);
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return NULL;
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}
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else {
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sllv_reverse(pstate->records);
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sllv_append(pstate->records, NULL);
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sllv_t* retval = pstate->records;
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pstate->records = sllv_alloc();
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return retval;
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}
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}
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