RPM Package Manager, CVS Repository
http://rpm5.org/cvs/
____________________________________________________________________________
Server: rpm5.org Name: Jeff Johnson
Root: /v/rpm/cvs Email: j...@rpm5.org
Module: rpm Date: 17-May-2015 01:32:03
Branch: rpm-5_4 Handle: 2015051623320300
Added files: (Branch: rpm-5_4)
rpm/rpmio tjson.c
Log:
- jsmn: simmple examples for twitter/github.
Summary:
Revision Changes Path
1.1.2.1 +520 -0 rpm/rpmio/tjson.c
____________________________________________________________________________
patch -p0 <<'@@ .'
Index: rpm/rpmio/tjson.c
============================================================================
$ cvs diff -u -r0 -r1.1.2.1 tjson.c
--- /dev/null 2015-05-17 01:30:38.000000000 +0200
+++ tjson.c 2015-05-17 01:32:03.426201299 +0200
@@ -0,0 +1,520 @@
+#include "system.h"
+#include <stdarg.h>
+#include <stdbool.h>
+#include <curl/curl.h>
+
+#include <rpmutil.h>
+
+#include "debug.h"
+
+#include "jsmn.c"
+
+/*==============================================================*/
+/* --- buf.h */
+
+typedef struct {
+ size_t len; // current length of buffer (used bytes)
+ size_t limit; // maximum length of buffer (allocated)
+ uint8_t *data; // insert bytes here
+} buf_t;
+
+
+buf_t *buf_size(buf_t * buf, size_t len);
+void buf_push(buf_t * buf, uint8_t c);
+void buf_concat(buf_t * buf, uint8_t * data, size_t len);
+char *buf_tostr(buf_t * buf);
+/*==============================================================*/
+/* --- json.h */
+
+char *json_fetch(char *url);
+jsmntok_t *json_tokenise(char *js);
+bool json_token_streq(char *js, jsmntok_t * t, char *s)
+ RPM_GNUC_PURE;
+char *json_token_tostr(char *js, jsmntok_t * t);
+/*==============================================================*/
+/* --- log.h */
+
+#define STR(x) #x
+#define STRINGIFY(x) STR(x)
+#define LINESTR STRINGIFY(__LINE__)
+
+#define log_assert(x) if (!(x)) log_die("%s: assertion failed: " #x \
+ " (" __FILE__ ", line " LINESTR \
+ ")", __func__)
+
+#define log_null(x) log_assert(x != NULL)
+
+#define log_debug(msg, ...) log_info("%s: " msg, __func__, ##__VA_ARGS__)
+
+#define log_syserr(msg) log_die("%s: %s: %s", __func__, msg, strerror(errno))
+
+void log_die(char *msg, ...)
+ RPM_GNUC_NORETURN;
+void log_info(char *msg, ...);
+/*==============================================================*/
+/* --- buf.c */
+/* buf: a sized buffer type. */
+
+buf_t *buf_size(buf_t * buf, size_t len)
+{
+ if (buf == NULL) {
+ buf = malloc(sizeof(buf_t));
+ log_null(buf);
+ buf->data = NULL;
+ buf->len = 0;
+ }
+
+ buf->data = realloc(buf->data, len);
+ log_null(buf->data);
+
+ if (buf->len > len)
+ buf->len = len;
+ buf->limit = len;
+
+ return buf;
+}
+
+void buf_push(buf_t * buf, uint8_t c)
+{
+ log_null(buf);
+
+ log_assert(buf->len < buf->limit);
+
+ buf->data[buf->len++] = c;
+}
+
+void buf_concat(buf_t * dst, uint8_t * src, size_t len)
+{
+ log_null(dst);
+ log_null(src);
+
+ log_assert(dst->len + len <= dst->limit);
+
+ for (size_t i = 0; i < len; i++)
+ dst->data[dst->len++] = src[i];
+}
+
+char *buf_tostr(buf_t * buf)
+{
+ log_null(buf);
+
+ char *str = malloc(buf->len + 1);
+
+ memcpy(str, buf->data, buf->len);
+ str[buf->len] = '\0';
+
+ return str;
+}
+
+/*==============================================================*/
+/* --- json.c */
+
+#define BUFFER_SIZE 32768
+#define JSON_TOKENS 256
+
+static size_t fetch_data(void *buffer, size_t size, size_t nmemb,
+ void *userp)
+{
+ buf_t *buf = (buf_t *) userp;
+ size_t total = size * nmemb;
+
+ if (buf->limit - buf->len < total) {
+ buf = buf_size(buf, buf->limit + total);
+ log_null(buf);
+ }
+
+ buf_concat(buf, buffer, total);
+
+ return total;
+}
+
+char *json_fetch(char *url)
+{
+ CURL *curl = curl_easy_init();
+ log_null(curl);
+
+ curl_easy_setopt(curl, CURLOPT_URL, url);
+
+ buf_t *buf = buf_size(NULL, BUFFER_SIZE);
+ curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fetch_data);
+ curl_easy_setopt(curl, CURLOPT_WRITEDATA, buf);
+ curl_easy_setopt(curl, CURLOPT_USERAGENT,
+ "jsmn-example (https://github.com/alisdair/jsmn-example,
alisd...@mcdiarmid.org)");
+
+ struct curl_slist *hs =
+ curl_slist_append(NULL, "Accept: application/json");
+ curl_easy_setopt(curl, CURLOPT_HTTPHEADER, hs);
+
+ CURLcode res = curl_easy_perform(curl);
+ if (res != CURLE_OK)
+ log_die("curl_easy_perform failed: %s", curl_easy_strerror(res));
+
+ curl_easy_cleanup(curl);
+ curl_slist_free_all(hs);
+
+ char *js = buf_tostr(buf);
+ free(buf->data);
+ free(buf);
+
+fprintf(stderr, "<-- %s(%s)\n%s\n", __FUNCTION__, url, js);
+ return js;
+}
+
+jsmntok_t *json_tokenise(char *js)
+{
+ jsmn_parser parser;
+ jsmn_init(&parser);
+
+ unsigned int n = JSON_TOKENS;
+ jsmntok_t *tokens = malloc(sizeof(jsmntok_t) * n);
+ log_null(tokens);
+
+ int ret = jsmn_parse(&parser, js, strlen(js), tokens, n);
+
+ while (ret == JSMN_ERROR_NOMEM) {
+ n = n * 2 + 1;
+ tokens = realloc(tokens, sizeof(jsmntok_t) * n);
+ log_null(tokens);
+ ret = jsmn_parse(&parser, js, strlen(js), tokens, n);
+ }
+
+ if (ret == JSMN_ERROR_INVAL)
+ log_die("jsmn_parse: invalid JSON string");
+ if (ret == JSMN_ERROR_PART)
+ log_die("jsmn_parse: truncated JSON string");
+
+ return tokens;
+}
+
+bool json_token_streq(char *js, jsmntok_t * t, char *s)
+{
+ return (strncmp(js + t->start, s, t->end - t->start) == 0
+ && strlen(s) == (size_t) (t->end - t->start));
+}
+
+char *json_token_tostr(char *js, jsmntok_t * t)
+{
+ js[t->end] = '\0';
+ return js + t->start;
+}
+
+/*==============================================================*/
+/* --- log.c */
+/* log: stderr logging information. */
+
+void log_die(char *msg, ...)
+{
+ va_list argp;
+
+ log_null(msg);
+
+ va_start(argp, msg);
+ vfprintf(stderr, msg, argp);
+ va_end(argp);
+
+ fprintf(stderr, "\n");
+ abort();
+}
+
+void log_info(char *msg, ...)
+{
+ va_list argp;
+
+ log_null(msg);
+
+ va_start(argp, msg);
+ vfprintf(stderr, msg, argp);
+ va_end(argp);
+
+ fprintf(stderr, "\n");
+}
+
+/*==============================================================*/
+/* --- twitter.c */
+
+#if defined(JSMN_TWITTER)
+char URL[] = "https://api.twitter.com/1.1/trends/1.json";;
+
+int main(void)
+{
+ char *js = json_fetch(URL);
+
+ jsmntok_t *tokens = json_tokenise(js);
+
+ /* The Twitter trends API response is in this format:
+ *
+ * [
+ * {
+ * ...,
+ * "trends": [
+ * {
+ * ...,
+ * "name": "TwitterChillers",
+ * },
+ * ...,
+ * ],
+ * ...,
+ * }
+ * ]
+ *
+ */
+ typedef enum {
+ START,
+ WRAPPER, OBJECT,
+ TRENDS, ARRAY,
+ TREND, NAME,
+ SKIP,
+ STOP
+ } parse_state;
+
+ // state is the current state of the parser
+ parse_state state = START;
+
+ // stack is the state we return to when reaching the end of an object
+ parse_state stack = STOP;
+
+ // Counters to keep track of how far through parsing we are
+ size_t object_tokens = 0;
+ size_t skip_tokens = 0;
+ size_t trends = 0;
+ size_t trend_tokens = 0;
+
+ for (size_t i = 0, j = 1; j > 0; i++, j--) {
+ jsmntok_t *t = &tokens[i];
+
+ // Should never reach uninitialized tokens
+ log_assert(t->start != -1 && t->end != -1);
+
+ if (t->type == JSMN_ARRAY || t->type == JSMN_OBJECT)
+ j += t->size;
+
+ switch (state) {
+ case START:
+ if (t->type != JSMN_ARRAY)
+ log_die("Invalid response: root element must be array.");
+ if (t->size != 1)
+ log_die("Invalid response: array must have one element.");
+
+ state = WRAPPER;
+ break;
+
+ case WRAPPER:
+ if (t->type != JSMN_OBJECT)
+ log_die("Invalid response: wrapper must be an object.");
+
+ state = OBJECT;
+ object_tokens = t->size;
+ break;
+
+ case OBJECT:
+ object_tokens--;
+
+ // Keys are odd-numbered tokens within the object
+ if (object_tokens % 2 == 1) {
+ if (t->type == JSMN_STRING
+ && json_token_streq(js, t, "trends"))
+ state = TRENDS;
+ } else if (t->type == JSMN_ARRAY || t->type == JSMN_OBJECT) {
+ state = SKIP;
+ stack = OBJECT;
+ skip_tokens = t->size;
+ }
+ // Last object value
+ if (object_tokens == 0)
+ state = STOP;
+
+ break;
+
+ case SKIP:
+ skip_tokens--;
+
+ if (t->type == JSMN_ARRAY || t->type == JSMN_OBJECT)
+ skip_tokens += t->size;
+
+ if (skip_tokens == 0)
+ state = stack;
+
+ break;
+
+ case TRENDS:
+ if (t->type != JSMN_ARRAY)
+ log_die("Unknown trends value: expected array.");
+
+ trends = t->size;
+ state = ARRAY;
+ stack = ARRAY;
+
+ // No trends found
+ if (trends == 0)
+ state = STOP;
+
+ break;
+
+ case ARRAY:
+ trends--;
+
+ trend_tokens = t->size;
+ state = TREND;
+
+ // Empty trend object
+ if (trend_tokens == 0)
+ state = STOP;
+
+ // Last trend object
+ if (trends == 0)
+ stack = STOP;
+
+ break;
+
+ case TREND:
+ case NAME:
+ trend_tokens--;
+
+ // Keys are odd-numbered tokens within the object
+ if (trend_tokens % 2 == 1) {
+ if (t->type == JSMN_STRING
+ && json_token_streq(js, t, "name"))
+ state = NAME;
+ }
+ // Only care about values in the NAME state
+ else if (state == NAME) {
+ if (t->type != JSMN_STRING)
+ log_die("Invalid trend name.");
+
+ char *str = json_token_tostr(js, t);
+ puts(str);
+
+ state = TREND;
+ } else if (t->type == JSMN_ARRAY || t->type == JSMN_OBJECT) {
+ state = SKIP;
+ stack = TREND;
+ skip_tokens = t->size;
+ }
+ // Last object value
+ if (trend_tokens == 0)
+ state = stack;
+
+ break;
+
+ case STOP:
+ // Just consume the tokens
+ break;
+
+ default:
+ log_die("Invalid state %u", state);
+ }
+ }
+
+ return 0;
+}
+#endif /* JSMN_TWITTER */
+
+/*==============================================================*/
+/* --- github.c */
+
+#if defined(JSMN_GITHUB)
+
+char URL[] = "https://api.github.com/users/alisdair";;
+char *KEYS[] = { "name", "location", "public_repos", "hireable" };
+
+int main(void)
+{
+ char *js = json_fetch(URL);
+
+ jsmntok_t *tokens = json_tokenise(js);
+
+ /* The GitHub user API response is a single object. States required to
+ * parse this are simple: start of the object, keys, values we want to
+ * print, values we want to skip, and then a marker state for the end. */
+
+ typedef enum { START, KEY, PRINT, SKIP, STOP } parse_state;
+ parse_state state = START;
+
+ size_t object_tokens = 0;
+
+ for (size_t i = 0, j = 1; j > 0; i++, j--) {
+ jsmntok_t *t = &tokens[i];
+
+ // Should never reach uninitialized tokens
+ log_assert(t->start != -1 && t->end != -1);
+
+ if (t->type == JSMN_ARRAY || t->type == JSMN_OBJECT)
+ j += 2 * t->size;
+
+ switch (state) {
+ case START:
+ if (t->type != JSMN_OBJECT)
+ log_die
+ ("Invalid response: root element must be an object.");
+
+ state = KEY;
+ object_tokens = 2 * t->size;
+
+ if (object_tokens == 0)
+ state = STOP;
+
+ if (object_tokens % 2 != 0)
+ log_die
+ ("Invalid response: object must have even number of
children.");
+
+ break;
+
+ case KEY:
+ object_tokens--;
+
+ if (t->type != JSMN_STRING)
+ log_die("Invalid response: object keys must be strings.");
+
+ state = SKIP;
+
+ for (size_t i = 0; i < sizeof(KEYS) / sizeof(char *); i++) {
+ if (json_token_streq(js, t, KEYS[i])) {
+ printf("%s: ", KEYS[i]);
+ state = PRINT;
+ break;
+ }
+ }
+
+ break;
+
+ case SKIP:
+ if (t->type != JSMN_STRING && t->type != JSMN_PRIMITIVE)
+ log_die
+ ("Invalid response: object values must be strings or
primitives.");
+
+ object_tokens--;
+ state = KEY;
+
+ if (object_tokens == 0)
+ state = STOP;
+
+ break;
+
+ case PRINT:
+ if (t->type != JSMN_STRING && t->type != JSMN_PRIMITIVE)
+ log_die
+ ("Invalid response: object values must be strings or
primitives.");
+
+ char *str = json_token_tostr(js, t);
+ puts(str);
+
+ object_tokens--;
+ state = KEY;
+
+ if (object_tokens == 0)
+ state = STOP;
+
+ break;
+
+ case STOP:
+ // Just consume the tokens
+ break;
+
+ default:
+ log_die("Invalid state %u", state);
+ }
+ }
+
+ return 0;
+}
+#endif /* JSMN_GITHUB */
@@ .
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