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104 lines
3.6 KiB
C
104 lines
3.6 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 "containers/lhmsi.h"
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#include "mapping/mappers.h"
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typedef struct _mapper_remove_empty_columns_state_t {
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sllv_t* precords;
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lhmsi_t* pnames_with_nonempty_values;
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} mapper_remove_empty_columns_state_t;
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static void mapper_remove_empty_columns_usage(FILE* o, char* argv0, char* verb);
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static mapper_t* mapper_remove_empty_columns_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_remove_empty_columns_alloc();
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static void mapper_remove_empty_columns_free(mapper_t* pmapper, context_t* _);
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static sllv_t* mapper_remove_empty_columns_process(lrec_t* pinrec, context_t* pctx, void* pvstate);
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// ----------------------------------------------------------------
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mapper_setup_t mapper_remove_empty_columns_setup = {
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.verb = "remove-empty-columns",
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.pusage_func = mapper_remove_empty_columns_usage,
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.pparse_func = mapper_remove_empty_columns_parse_cli,
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.ignores_input = FALSE,
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};
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// ----------------------------------------------------------------
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static void mapper_remove_empty_columns_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, "Omits fields which are empty on every input row. Non-streaming.\n");
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}
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static mapper_t* mapper_remove_empty_columns_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_remove_empty_columns_usage(stderr, argv[0], argv[*pargi]);
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return NULL;
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}
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mapper_t* pmapper = mapper_remove_empty_columns_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_remove_empty_columns_alloc() {
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mapper_t* pmapper = mlr_malloc_or_die(sizeof(mapper_t));
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mapper_remove_empty_columns_state_t* pstate = mlr_malloc_or_die(sizeof(mapper_remove_empty_columns_state_t));
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pstate->precords = sllv_alloc();
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pstate->pnames_with_nonempty_values = lhmsi_alloc();
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pmapper->pvstate = pstate;
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pmapper->pprocess_func = mapper_remove_empty_columns_process;
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pmapper->pfree_func = mapper_remove_empty_columns_free;
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return pmapper;
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}
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static void mapper_remove_empty_columns_free(mapper_t* pmapper, context_t* _) {
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mapper_remove_empty_columns_state_t* pstate = pmapper->pvstate;
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// Free the container
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sllv_free(pstate->precords);
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lhmsi_free(pstate->pnames_with_nonempty_values);
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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_remove_empty_columns_process(lrec_t* pinrec, context_t* pctx, void* pvstate) {
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mapper_remove_empty_columns_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->precords, pinrec);
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for (lrece_t* pe = pinrec->phead; pe != NULL; pe = pe->pnext) {
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if (pe->value[0] != 0) {
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if (!lhmsi_has_key(pstate->pnames_with_nonempty_values, pe->key)) {
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lhmsi_put(pstate->pnames_with_nonempty_values, mlr_strdup_or_die(pe->key), 1, FREE_ENTRY_KEY);
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}
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}
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}
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return NULL;
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}
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else {
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for (sllve_t* pe = pstate->precords->phead; pe != NULL; pe = pe->pnext) {
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lrec_t* prec = pe->pvvalue;
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lrece_t* pf = prec->phead;
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while (pf != NULL) {
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if (lhmsi_has_key(pstate->pnames_with_nonempty_values, pf->key)) {
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pf = pf->pnext;
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} else {
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lrece_t* pnext = pf->pnext;
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lrec_unlink_and_free(prec, pf);
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pf = pnext;
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}
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}
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}
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sllv_append(pstate->precords, NULL);
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sllv_t* retval = pstate->precords;
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pstate->precords = sllv_alloc();
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return retval;
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}
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}
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