Switch formatting from AWK to a C program.

Due mostly to poor performance, calling out to the shell for time
formatting quickly degrades in performance with a large list, this
solves that problem. Yes, `gawk` has strftime, no, I don't want to use
gawk.

1 files changed, 277 insertions, 0 deletions

diff --git a/pm-fmtdb.c b/pm-fmtdb.c
new file mode 100644
index 0000000..2683112
--- /dev/null
+++ b/pm-fmtdb.c
@@ -0,0 +1,277 @@
+/*
+ * Copyright (c) 2023 Mitchell Riedstra
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Small program for quickly formatting the database file, reads it in,
+ * formats the date and spits it out in reversed order.
+ * Format is easily adjusted below at compile time.
+ *
+ */
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#define TIME_FMT_CREATED "%H:%M:%S %m.%d.%y"
+#define TIME_FMT_UPDATED "%m.%d.%y"
+
+/* Format string for the dump output */
+#define OUTPUT_FMT "ID: %s Updated: %s Name: %-60s Content %s\n"
+/* See the Entry struct below for available fields */
+#define OUTPUT_FMT_ARGS cur->Id, updated, cur->name, cur->content
+
+/* 
+ * Be careful changing this one, the `pm` shell script will need to be updated
+ * too.
+ */
+#define DB_DELIM "::"
+
+#define TIME_FMT_MAX 256
+#define ENTRY_MAX 1024
+
+struct Entry {
+	char *Id;
+	time_t created;
+	time_t updated;
+	char *name;
+	char *content;
+
+	struct Entry *next;
+	struct Entry *prev;
+};
+
+void
+help()
+{
+	puts("pm-fmtdb [-f <file>]");
+	exit(1);
+}
+
+void
+die(const char *msg)
+{
+	perror(msg);
+	exit(1);
+}
+
+void *
+ecalloc(size_t nmemb, size_t size)
+{
+	void *ret;
+	ret = calloc(nmemb, size);
+	if (!ret) {
+		die("calloc");
+	}
+	return ret;
+}
+
+int
+FmtTimestamp(char **dest, time_t t, const char *fmt, size_t bufsize)
+{
+	struct tm *tm;
+	char *out = ecalloc(bufsize, sizeof(char *));
+
+	tm = localtime(&t);
+
+	if (strftime(out, bufsize, fmt, tm) == 0) {
+		free(out);
+		return -1;
+	}
+
+	*dest = out;
+	return 0;
+}
+
+char **
+charArrAppend(char **arr, size_t curlen, char *s)
+{
+	arr = reallocarray(arr, curlen+1, sizeof(char **));
+	if (!arr) {
+		die("reallocarray");
+	}
+
+	arr[curlen] = s;
+	return arr;
+}
+
+
+char **
+split(char *buf, const char *delim) {
+	int outlen = 0;
+	int len = strlen(buf);
+	char **out = NULL;
+	int dl = strlen(delim);
+	int dpos = 0;
+
+	int s = 0;
+	for (int n = 0; n < len; n++) {
+		
+		if (buf[n] == '\n') {
+			char *str = ecalloc(n-s+1, sizeof(char *));
+			strncpy(str, &buf[s], n-s);
+			out = charArrAppend(out, outlen++, str);
+			break;
+		}
+
+		if (dpos+1 == dl && buf[n] == delim[dpos]) {
+			char *str = ecalloc((n-s)+1, sizeof(char *));
+			strncpy(str, &buf[s], n-dl-s+1);
+			s = n+1;
+
+			out = charArrAppend(out, outlen++, str);
+
+			dpos = 0;
+			continue;
+		}
+		
+		if (buf[n] == delim[dpos]) {
+			dpos++;
+		} else {
+			dpos = 0;
+		}
+
+	}
+	return charArrAppend(out, outlen++, NULL);
+}
+
+struct Entry *
+loadEntries(FILE *f) {
+	int ret;
+	size_t max = ENTRY_MAX;
+	char *buf = ecalloc(max, sizeof(char *));
+	char **fields;
+	struct Entry *e = ecalloc(1, sizeof(struct Entry));
+	struct Entry *eprev = NULL;
+	int n;
+
+	for (;;) {
+		ret = getdelim(&buf, &max, '\n', f);
+		if (ret == -1 && ret != EOF) {
+			die("read");
+		} 
+
+		if (ret == EOF)
+			break;
+
+		fields = split(buf, DB_DELIM);
+		char **f = fields;
+		for (n = 0;*f;f++) {
+			switch(n) {
+			case 0:
+				e->Id = *f;
+				break;
+			case 1:
+				errno = 0;
+				e->created = strtol(*f, NULL, 10);
+				if (errno != 0)
+					perror("bad timestamp: strtol");
+				break;
+			case 2:
+				errno = 0;
+				e->updated = strtol(*f, NULL, 10);
+				if (errno != 0)
+					perror("bad timestamp: strtol");
+				break;
+			case 3:
+				e->name = *f;
+				break;
+			case 4:
+				e->content = *f;
+			}
+			n++;
+		}
+
+		eprev = e;
+		e = ecalloc(1, sizeof(struct Entry));
+		eprev->next = e;
+		e->prev = eprev;
+	}
+
+	free(buf); buf = NULL;
+
+	return eprev;
+}
+
+char *
+strAppend(char *a, char *b)
+{
+	int alen = strlen(a);
+	char *n = ecalloc(alen+strlen(b)+1, sizeof(char));
+	strcpy(n, a);
+	strcpy(n+alen, b);
+	return n;
+}
+
+void
+dumpDB(FILE *db)
+{
+	struct Entry *cur, *last;
+	last = loadEntries(db);
+	if (!last) {
+		puts("Failed to load entries");
+		exit(1);
+	}
+
+	for (cur = last; cur; cur = cur->prev) {
+		char *updated;
+		if (FmtTimestamp(&updated, cur->updated, TIME_FMT_UPDATED,
+					TIME_FMT_MAX) == -1) {
+			die("FmtTimestamp");
+		}
+		char *created;
+		if (FmtTimestamp(&created, cur->created, TIME_FMT_CREATED,
+					TIME_FMT_MAX) == -1) {
+			die("FmtTimestamp");
+		}
+
+		printf(OUTPUT_FMT, OUTPUT_FMT_ARGS);
+		free(updated); updated = NULL;
+	}
+}
+
+int
+main(int argc, char **argv) {
+	char *fn = getenv("PASTE_MANAGER_FILE");
+	char **a = argv+1;
+	FILE *f;
+
+	for (;*a;a++) {
+		if (strcmp(*a, "-f") == 0 && *(++a)) {
+			fn = *a;
+		} else {
+			if (*a)
+				printf("Unknown option: '%s'\n", *a);
+
+			help();
+		}
+	}
+
+	if (!fn) {
+		fn = strAppend(getenv("HOME"), "/.pastes");
+	}
+
+	if (*fn == '-') {
+		f = stdin;
+	} else {
+		f = fopen(fn, "r");
+		if (!f) {
+			die("open");
+		}
+	}
+
+	dumpDB(f);
+}