miller/c/output/multi_lrec_writer.c

#include "lib/mlrutil.h"
#include "lib/mlr_globals.h"
#include "cli/mlrcli.h"
#include "output/multi_lrec_writer.h"

// ----------------------------------------------------------------
multi_lrec_writer_t* multi_lrec_writer_alloc(cli_writer_opts_t* pwriter_opts) {
	multi_lrec_writer_t* pmlw = mlr_malloc_or_die(sizeof(multi_lrec_writer_t));
	pmlw->pnames_to_lrec_writers_and_fps = lhmsv_alloc();
	pmlw->pwriter_opts = pwriter_opts;
	return pmlw;
}

// ----------------------------------------------------------------
void multi_lrec_writer_free(multi_lrec_writer_t* pmlw) {
	if (pmlw == NULL)
		return;

	for (lhmsve_t* pe = pmlw->pnames_to_lrec_writers_and_fps->phead; pe != NULL; pe = pe->pnext) {
		lrec_writer_and_fp_t* pstate = pe->pvvalue;
		pstate->plrec_writer->pfree_func(pstate->plrec_writer);
		free(pstate->filename_or_command);
		free(pstate);
	}

	lhmsv_free(pmlw->pnames_to_lrec_writers_and_fps);
	free(pmlw);
}

// ----------------------------------------------------------------
void multi_lrec_writer_output_srec(multi_lrec_writer_t* pmlw, lrec_t* poutrec, char* filename_or_command,
	file_output_mode_t file_output_mode, int flush_every_record)
{
	lrec_writer_and_fp_t* pstate = lhmsv_get(pmlw->pnames_to_lrec_writers_and_fps, filename_or_command);
	if (pstate == NULL) {
		pstate = mlr_malloc_or_die(sizeof(lrec_writer_and_fp_t));
		pstate->plrec_writer = lrec_writer_alloc(pmlw->pwriter_opts);
		MLR_INTERNAL_CODING_ERROR_IF(pstate->plrec_writer == NULL);
		pstate->filename_or_command = mlr_strdup_or_die(filename_or_command);
		char* mode_string = get_mode_string(file_output_mode);
		char* mode_desc = get_mode_desc(file_output_mode);
		if (file_output_mode == MODE_PIPE) {
			pstate->is_popen = TRUE;
			pstate->output_stream = popen(filename_or_command, mode_string);
			if (pstate->output_stream == NULL) {
				perror("popen");
				fprintf(stderr, "%s: failed popen for %s on \"%s\".\n",
					MLR_GLOBALS.bargv0, mode_desc, filename_or_command);
				exit(1);
			}
		} else {
			pstate->is_popen = FALSE;
			pstate->output_stream = fopen(filename_or_command, mode_string);
			if (pstate->output_stream == NULL) {
				perror("fopen");
				fprintf(stderr, "%s: failed fopen for %s on \"%s\".\n",
					MLR_GLOBALS.bargv0, mode_desc, filename_or_command);
				exit(1);
			}
		}

		lhmsv_put(pmlw->pnames_to_lrec_writers_and_fps, mlr_strdup_or_die(filename_or_command), pstate, FREE_ENTRY_KEY);
	}

	pstate->plrec_writer->pprocess_func(pstate->plrec_writer->pvstate, pstate->output_stream, poutrec);

	if (poutrec != NULL) {
		if (flush_every_record)
			fflush(pstate->output_stream);
	} else {
		if (pstate->is_popen) {
			// Sadly, pclose returns an error even on well-formed commands. For example, if the popened
			// command was "grep nonesuch" and the string "nonesuch" was not encountered, grep returns
			// non-zero and popen flags it as an error. We cannot differentiate these from genuine
			// failure cases so the best choice is to simply call pclose and ignore error codes.
			// If a piped-to command does fail then it should have some output to stderr which the
			// user can take advantage of.
			(void)pclose(pstate->output_stream);
		} else {
			if (fclose(pstate->output_stream) != 0) {
				perror("fclose");
				fprintf(stderr, "%s: fclose error on \"%s\".\n", MLR_GLOBALS.bargv0, filename_or_command);
				exit(1);
			}
		}
		pstate->output_stream = NULL;
	}
}

void multi_lrec_writer_output_list(multi_lrec_writer_t* pmlw, sllv_t* poutrecs, char* filename_or_command,
	file_output_mode_t file_output_mode, int flush_every_record)
{
	if (poutrecs == NULL) // synonym for empty record-list
		return;

	while (poutrecs->phead) {
		lrec_t* poutrec = sllv_pop(poutrecs);
		multi_lrec_writer_output_srec(pmlw, poutrec, filename_or_command, file_output_mode, flush_every_record);
	}
}

void multi_lrec_writer_drain(multi_lrec_writer_t* pmlw) {
	for (lhmsve_t* pe = pmlw->pnames_to_lrec_writers_and_fps->phead; pe != NULL; pe = pe->pnext) {
		lrec_writer_and_fp_t* pstate = pe->pvvalue;
		pstate->plrec_writer->pprocess_func(pstate->plrec_writer->pvstate, pstate->output_stream, NULL);
		fflush(pstate->output_stream);
		if (pstate->is_popen) {
			// Sadly, pclose returns an error even on well-formed commands. For example, if the popened
			// command was "grep nonesuch" and the string "nonesuch" was not encountered, grep returns
			// non-zero and popen flags it as an error. We cannot differentiate these from genuine
			// failure cases so the best choice is to simply call pclose and ignore error codes.
			// If a piped-to command does fail then it should have some output to stderr which the
			// user can take advantage of.
			(void)pclose(pstate->output_stream);
		} else {
			if (fclose(pstate->output_stream) != 0) {
				perror("fclose");
				fprintf(stderr, "%s: fclose error on \"%s\".\n", MLR_GLOBALS.bargv0, pstate->filename_or_command);
				exit(1);
			}
		}
	}
}