HEADmaster

3 files changed, 178 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..208d9ce
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+d
+db
+core
diff --git a/d.c b/d.c
new file mode 100644
index 0000000..eefdece
--- /dev/null
+++ b/d.c
@@ -0,0 +1,171 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <time.h>
+#include <string.h>
+#include <sys/types.h>
+#include <error.h>
+#include <endian.h>
+#include <inttypes.h>
+#include <curl/curl.h>
+#include <cjson/cJSON.h>
+#define S0(x) (x ? x : "")
+enum entry {
+	TALLY,
+	QUOTA
+};
+#define TYPE_SHIFT (8*7)
+#define STATION_SHIFT (8*6)
+#define VALUE_SHIFT (8*5)
+#define TYPE_INS(x) ((uint64_t) x << TYPE_SHIFT)
+#define STATION_INS(x) ((uint64_t) x << STATION_SHIFT)
+#define VALUE_INS(x) ((uint64_t) x << VALUE_SHIFT)
+#define TYPE_RET(x) ((x & TYPE_INS(0xFF)) >> TYPE_SHIFT)
+#define STATION_RET(x) ((x & STATION_INS(0xFF)) >> STATION_SHIFT)
+#define VALUE_RET(x) ((x & VALUE_INS(0xFF)) >> VALUE_SHIFT)
+#define TIME 0xFFFFFFFF
+char * response = NULL;
+size_t response_len = 0;
+size_t write_callback (char * ptr, size_t size, size_t nmemb, void * userdata __attribute__((unused))) {
+	nmemb *= size;
+	char * mem = realloc(response, response_len+nmemb+1);
+	if (!mem)
+		return 0;
+	response = mem;
+	strncpy(response+response_len, ptr, nmemb);
+	response[(response_len += nmemb)] = '\0';
+	return nmemb;
+}
+int main (int argc, char ** argv) {
+	cJSON * json = NULL;
+	int r = 0;
+	CURL * curl = NULL;
+	unsigned char tally[256];
+	unsigned char quota[256];
+	memset(tally, 255, 256);
+	memset(quota, 255, 256);
+	if (fseek(stdin, -8, SEEK_END) == -1) {
+		if (errno == EINVAL)
+			fprintf(stderr, "nova (prazna) podatkovna zbirka!\n");
+		else
+			error_at_line(1, errno, __FILE__, __LINE__, "fseek. uporaba: %s >> db < db", S0(argv[0]));
+	}
+	uint64_t entry;
+	while (fread(&entry, sizeof entry, 1,  stdin)) {
+		entry = be64toh(entry);
+		char čas[256];
+		time_t time = entry & TIME;
+		strftime(čas, 256, "%c", localtime(&time));
+		switch (TYPE_RET(entry)) {
+			case TALLY:
+				if (tally[STATION_RET(entry)] == 255) {
+					tally[STATION_RET(entry)] = VALUE_RET(entry);
+					fprintf(stderr, "[db] %s: na postaji %" PRIu64 " je %" PRIu64 " koles\n", čas, STATION_RET(entry), VALUE_RET(entry));
+				}
+				break;
+			case QUOTA:
+				if (quota[STATION_RET(entry)] == 255) {
+					quota[STATION_RET(entry)] = VALUE_RET(entry);
+					fprintf(stderr, "[db] %s: na postaji %" PRIu64 " je %" PRIu64 " postajališč\n", čas, STATION_RET(entry), VALUE_RET(entry));
+				}
+				break;
+			default:
+				error_at_line(2, 0, __FILE__, __LINE__, "invalid entry with type %" PRIu64, TYPE_RET(entry));
+		}
+		if (fseek(stdin, -16, SEEK_CUR) == -1)
+			break;
+	}
+	char curlerr[CURL_ERROR_SIZE];
+	curl = curl_easy_init();
+	if (!curl)
+		error_at_line(2, 0, __FILE__, __LINE__, "!curl");
+	curl_easy_setopt(curl, CURLOPT_URL, "https://api.jcdecaux.com/vls/v3/stations?apiKey=frifk0jbxfefqqniqez09tw4jvk37wyf823b5j1i&contract=ljubljana");
+	curl_easy_setopt(curl,  CURLOPT_ERRORBUFFER, curlerr);
+	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_callback);
+	char buf[256];
+	snprintf(buf, 255, "bicikelj-stat/0.0.0 sends at most one request per 50 seconds. contact by email: %s", argc > 1 ? argv[1] : "not provided");
+	curl_easy_setopt(curl, CURLOPT_USERAGENT, buf);
+	while (1) {
+		fprintf(stderr, ".");
+		curlerr[0] = '\0';
+		response_len = 0;
+		CURLcode res = curl_easy_perform(curl);
+		if (res != CURLE_OK) {
+			error_at_line(0, 0, __FILE__, __LINE__, "!= CURLE_OK: %s", curlerr[0] ? curlerr : curl_easy_strerror(res));
+			r = 3;
+			goto r;
+		}
+		json = cJSON_Parse(response);
+		cJSON * station = NULL;
+		cJSON_ArrayForEach(station, json) {
+			cJSON * number = cJSON_GetObjectItem(station, "number");
+			cJSON * name = cJSON_GetObjectItem(station, "name");
+			cJSON * capacity = cJSON_GetObjectItem(cJSON_GetObjectItem(station, "totalStands"), "capacity");
+			cJSON * bikes = cJSON_GetObjectItem(cJSON_GetObjectItem(cJSON_GetObjectItem(station, "totalStands"), "availabilities"), "bikes");
+			if (!cJSON_IsNumber(number)) {
+				error_at_line(0, 0, __FILE__, __LINE__, "number");
+				r = 4;
+				goto r;
+			}
+			if (!cJSON_IsNumber(capacity)) {
+				error_at_line(0, 0, __FILE__, __LINE__, "capacity");
+				r = 5;
+				goto r;
+			}
+			if (!cJSON_IsNumber(bikes)) {
+				error_at_line(0, 0, __FILE__, __LINE__, "bikes");
+				r = 6;
+				goto r;
+			}
+			if (!cJSON_IsString(name)) {
+				error_at_line(0, 0, __FILE__, __LINE__, "name");
+				r = 7;
+				goto r;
+			}
+			if (number->valueint >= 255 || capacity->valueint >= 255 || bikes->valueint >= 255) {
+				error_at_line(0, 0, __FILE__, __LINE__, "number || capacity || bikes >= 255: evil server!");
+				r = 8;
+				goto r;
+			}
+
+			char čas[256];
+			time_t tajm = entry = time(NULL);
+			strftime(čas, 256, "%c", localtime(&tajm));
+			if (quota[number->valueint] != capacity->valueint) {
+				unsigned old = quota[number->valueint];
+				entry |= TYPE_INS(QUOTA) | STATION_INS(number->valueint) | VALUE_INS(capacity->valueint);
+				if (old == 255)
+					fprintf(stderr, "%s: na postaji %s (%d) je %d postajališč\n", čas, name->valuestring, number->valueint, capacity->valueint);
+				else
+					fprintf(stderr, "%s: na postaji %s (%d) je %d postajališč (prej %u)\n", čas, name->valuestring, number->valueint, capacity->valueint, old);
+				quota[number->valueint] = capacity->valueint;
+				entry = htobe64(entry);
+				fwrite(&entry, sizeof entry, 1, stdout);
+			}
+			entry = time(NULL);
+			if (tally[number->valueint] != bikes->valueint) {
+				unsigned old = tally[number->valueint];
+				entry |= TYPE_INS(TALLY) | STATION_INS(number->valueint) | VALUE_INS(bikes->valueint);
+				if (old == 255)
+					fprintf(stderr, "%s: na postaji %s (%d) je %d koles\n", čas, name->valuestring, number->valueint, bikes->valueint);
+				else
+					fprintf(stderr, "%s: na postaji %s (%d) je %d koles (prej %u)\n", čas, name->valuestring, number->valueint, bikes->valueint, old);
+				tally[number->valueint] = bikes->valueint;
+				entry = htobe64(entry);
+				fwrite(&entry, sizeof entry, 1, stdout);
+			}
+			fflush(stdout);
+		}
+		cJSON_Delete(json);
+		json = NULL;
+		sleep(50);
+	}
+r:
+	cJSON_Delete(json);
+	json = NULL;
+	curl_easy_cleanup(curl);
+	curl = NULL;
+	free(response);
+	return r;
+}
diff --git a/makefile b/makefile
new file mode 100644
index 0000000..f5eb442
--- /dev/null
+++ b/makefile
@@ -0,0 +1,4 @@
+default:
+	 gcc -Wextra -Wformat-security -Wall -pedantic -O0 -g d.c -od -lcurl -lcjson
+run:
+	./d >> db < db