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authorJosé Bollo <jose.bollo@iot.bzh>2017-07-26 20:02:13 +0200
committerJosé Bollo <jose.bollo@iot.bzh>2017-07-27 16:54:43 +0200
commit4a3d0c568ec5ee1296f4a50f269a1eadc4898e27 (patch)
treeee383f144ed1eeb7b0b2a541157928586d496835
parentfee037ca12807a45527b78ca6bcffcdc9a7afabc (diff)
wrap-json: add packing tool for json
The functions wrap_json_pack and wrap_json_vpack can be used to create json object. These functions are likely to be compatible in the format with the packing functions of the library jansson [1]. [1] http://jansson.readthedocs.io/en/2.10/apiref.html#building-values Change-Id: I2e251bdb9b590ba55707c5a9ed60528cad927fb3 Signed-off-by: José Bollo <jose.bollo@iot.bzh>
-rw-r--r--src/wrap-json.c402
-rw-r--r--src/wrap-json.h29
2 files changed, 431 insertions, 0 deletions
diff --git a/src/wrap-json.c b/src/wrap-json.c
new file mode 100644
index 00000000..1b4b13ea
--- /dev/null
+++ b/src/wrap-json.c
@@ -0,0 +1,402 @@
+/*
+ Copyright (C) 2016, 2017 "IoT.bzh"
+
+ author: José Bollo <jose.bollo@iot.bzh>
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+#include <string.h>
+
+#include "wrap-json.h"
+
+#define STACKCOUNT 32
+#define STRCOUNT 8
+
+enum {
+ wrap_json_pack_error_none,
+ wrap_json_pack_error_null_object,
+ wrap_json_pack_error_truncated,
+ wrap_json_pack_error_internal_error,
+ wrap_json_pack_error_out_of_memory,
+ wrap_json_pack_error_invalid_character,
+ wrap_json_pack_error_too_long,
+ wrap_json_pack_error_too_deep,
+ wrap_json_pack_error_null_spec,
+ wrap_json_pack_error_null_key,
+ wrap_json_pack_error_null_string,
+ _wrap_json_pack_error_count_
+};
+
+static const char ignore_all[] = " \t\n\r,:";
+static const char accept_arr[] = "][{snbiIfoO";
+static const char accept_key[] = "s}";
+#define accept_any (&accept_arr[1])
+
+static const char *pack_errors[_wrap_json_pack_error_count_] =
+{
+ [wrap_json_pack_error_none] = "unknown error",
+ [wrap_json_pack_error_null_object] = "null object",
+ [wrap_json_pack_error_truncated] = "truncated",
+ [wrap_json_pack_error_internal_error] = "internal error",
+ [wrap_json_pack_error_out_of_memory] = "out of memory",
+ [wrap_json_pack_error_invalid_character] = "invalid character",
+ [wrap_json_pack_error_too_long] = "too long",
+ [wrap_json_pack_error_too_deep] = "too deep",
+ [wrap_json_pack_error_null_spec] = "spec is NULL",
+ [wrap_json_pack_error_null_key] = "key is NULL",
+ [wrap_json_pack_error_null_string] = "string is NULL"
+};
+
+int wrap_json_pack_error_position(int rc)
+{
+ if (rc < 0)
+ rc = -rc;
+ return (rc >> 4) + 1;
+}
+
+int wrap_json_pack_error_code(int rc)
+{
+ if (rc < 0)
+ rc = -rc;
+ return rc & 15;
+}
+
+const char *wrap_json_pack_error_string(int rc)
+{
+ rc = wrap_json_pack_error_code(rc);
+ if (rc >= sizeof pack_errors / sizeof *pack_errors)
+ rc = 0;
+ return pack_errors[rc];
+}
+
+
+
+static inline const char *skip(const char *d)
+{
+ while (*d && strchr(ignore_all, *d))
+ d++;
+ return d;
+}
+
+int wrap_json_vpack(struct json_object **result, const char *desc, va_list args)
+{
+ int nstr, notnull, nullable, rc;
+ size_t sz, dsz, ssz;
+ char *s;
+ char c;
+ const char *d;
+ char buffer[256];
+ struct { const char *str; size_t sz; } strs[STRCOUNT];
+ struct { struct json_object *cont, *key; const char *acc; char type; } stack[STACKCOUNT], *top;
+ struct json_object *obj;
+
+ ssz = sizeof buffer;
+ s = buffer;
+ top = stack;
+ top->key = NULL;
+ top->cont = NULL;
+ top->acc = accept_any;
+ top->type = 0;
+ if (!desc)
+ goto null_spec;
+ d = skip(desc);
+ for(;;) {
+ c = *d;
+ if (!c)
+ goto truncated;
+ if (!strchr(top->acc, c))
+ goto invalid_character;
+ d = skip(++d);
+ switch(c) {
+ case 's':
+ nullable = 0;
+ notnull = 0;
+ nstr = 0;
+ sz = 0;
+ for (;;) {
+ strs[nstr].str = va_arg(args, const char*);
+ if (strs[nstr].str)
+ notnull = 1;
+ if (*d == '?') {
+ d = skip(++d);
+ nullable = 1;
+ }
+ switch(*d) {
+ case '%': strs[nstr].sz = va_arg(args, size_t); d = skip(++d); break;
+ case '#': strs[nstr].sz = (size_t)va_arg(args, int); d = skip(++d); break;
+ default: strs[nstr].sz = strs[nstr].str ? strlen(strs[nstr].str) : 0; break;
+ }
+ sz += strs[nstr++].sz;
+ if (*d == '?') {
+ d = skip(++d);
+ nullable = 1;
+ }
+ if (*d != '+')
+ break;
+ if (nstr >= STRCOUNT)
+ goto too_long;
+ d = skip(++d);
+ }
+ if (*d == '*')
+ nullable = 1;
+ if (notnull) {
+ if (sz > ssz) {
+ ssz += ssz;
+ if (ssz < sz)
+ ssz = sz;
+ s = alloca(sz);
+ }
+ dsz = sz;
+ while (nstr) {
+ nstr--;
+ dsz -= strs[nstr].sz;
+ memcpy(&s[dsz], strs[nstr].str, strs[nstr].sz);
+ }
+ obj = json_object_new_string_len(s, sz);
+ if (!obj)
+ goto out_of_memory;
+ } else if (nullable)
+ obj = NULL;
+ else
+ goto null_string;
+ break;
+ case 'n':
+ obj = NULL;
+ break;
+ case 'b':
+ obj = json_object_new_boolean(va_arg(args, int));
+ if (!obj)
+ goto out_of_memory;
+ break;
+ case 'i':
+ obj = json_object_new_int(va_arg(args, int));
+ if (!obj)
+ goto out_of_memory;
+ break;
+ case 'I':
+ obj = json_object_new_int64(va_arg(args, int64_t));
+ if (!obj)
+ goto out_of_memory;
+ break;
+ case 'f':
+ obj = json_object_new_double(va_arg(args, double));
+ if (!obj)
+ goto out_of_memory;
+ break;
+ case 'o':
+ case 'O':
+ obj = va_arg(args, struct json_object*);
+ if (*d == '?')
+ d = skip(++d);
+ else if (*d != '*' && !obj)
+ goto null_object;
+ if (c == 'O')
+ json_object_get(obj);
+ break;
+ case '[':
+ case '{':
+ if (++top >= &stack[STACKCOUNT])
+ goto too_deep;
+ top->key = NULL;
+ if (c == '[') {
+ top->type = ']';
+ top->acc = accept_arr;
+ top->cont = json_object_new_array();
+ } else {
+ top->type = '}';
+ top->acc = accept_key;
+ top->cont = json_object_new_object();
+ }
+ if (!top->cont)
+ goto out_of_memory;
+ continue;
+ case '}':
+ case ']':
+ if (c != top->type || top <= stack)
+ goto invalid_character;
+ obj = (top--)->cont;
+ if (*d == '*' && !(c == '}' ? json_object_object_length(obj) : json_object_array_length(obj))) {
+ json_object_put(obj);
+ obj = NULL;
+ }
+ break;
+ default:
+ goto internal_error;
+ }
+ switch (top->type) {
+ case 0:
+ if (top != stack)
+ goto internal_error;
+ if (*d)
+ goto invalid_character;
+ *result = obj;
+ return 0;
+ case ']':
+ if (obj || *d != '*')
+ json_object_array_add(top->cont, obj);
+ if (*d == '*')
+ d = skip(++d);
+ break;
+ case '}':
+ if (!obj)
+ goto null_key;
+ top->key = obj;
+ top->acc = accept_any;
+ top->type = ':';
+ break;
+ case ':':
+ if (obj || *d != '*')
+ json_object_object_add(top->cont, json_object_get_string(top->key), obj);
+ if (*d == '*')
+ d = skip(++d);
+ json_object_put(top->key);
+ top->key = NULL;
+ top->acc = accept_key;
+ top->type = '}';
+ break;
+ }
+ }
+
+null_object:
+ rc = wrap_json_pack_error_null_object;
+ goto error;
+truncated:
+ rc = wrap_json_pack_error_truncated;
+ goto error;
+internal_error:
+ rc = wrap_json_pack_error_internal_error;
+ goto error;
+out_of_memory:
+ rc = wrap_json_pack_error_out_of_memory;
+ goto error;
+invalid_character:
+ rc = wrap_json_pack_error_invalid_character;
+ goto error;
+too_long:
+ rc = wrap_json_pack_error_too_long;
+ goto error;
+too_deep:
+ rc = wrap_json_pack_error_too_deep;
+ goto error;
+null_spec:
+ rc = wrap_json_pack_error_null_spec;
+ goto error;
+null_key:
+ rc = wrap_json_pack_error_null_key;
+ goto error;
+null_string:
+ rc = wrap_json_pack_error_null_string;
+ goto error;
+error:
+ do {
+ json_object_put(top->key);
+ json_object_put(top->cont);
+ } while (--top >= stack);
+ *result = NULL;
+ rc = rc | (int)((d - desc) << 4);
+ return -rc;
+}
+
+int wrap_json_pack(struct json_object **result, const char *desc, ...)
+{
+ int rc;
+ va_list args;
+
+ va_start(args, desc);
+ rc = wrap_json_vpack(result, desc, args);
+ va_end(args);
+ return rc;
+}
+
+#if 1
+#include <stdio.h>
+
+void T(const char *desc, ...)
+{
+ int rc;
+ va_list args;
+ struct json_object *result;
+
+ va_start(args, desc);
+ rc = wrap_json_vpack(&result, desc, args);
+ va_end(args);
+ if (!rc)
+ printf(" SUCCESS %s\n\n", json_object_to_json_string(result));
+ else
+ printf(" ERROR[char %d err %d] %s\n\n", wrap_json_pack_error_position(rc), wrap_json_pack_error_code(rc), wrap_json_pack_error_string(rc));
+ json_object_put(result);
+}
+
+#define t(...) printf("testing(%s)\n",#__VA_ARGS__); T(__VA_ARGS__);
+
+int main()
+{
+ char buffer[4] = {'t', 'e', 's', 't'};
+
+ t("n");
+ t("b", 1);
+ t("b", 0);
+ t("i", 1);
+ t("I", (uint64_t)0x123456789abcdef);
+ t("f", 3.14);
+ t("s", "test");
+ t("s?", "test");
+ t("s?", NULL);
+ t("s#", "test asdf", 4);
+ t("s%", "test asdf", (size_t)4);
+ t("s#", buffer, 4);
+ t("s%", buffer, (size_t)4);
+ t("s++", "te", "st", "ing");
+ t("s#+#+", "test", 1, "test", 2, "test");
+ t("s%+%+", "test", (size_t)1, "test", (size_t)2, "test");
+ t("{}", 1.0);
+ t("[]", 1.0);
+ t("o", json_object_new_int(1));
+ t("o?", json_object_new_int(1));
+ t("o?", NULL);
+ t("O", json_object_new_int(1));
+ t("O?", json_object_new_int(1));
+ t("O?", NULL);
+ t("{s:[]}", "foo");
+ t("{s+#+: []}", "foo", "barbar", 3, "baz");
+ t("{s:s,s:o,s:O}", "a", NULL, "b", NULL, "c", NULL);
+ t("{s:**}", "a", NULL);
+ t("{s:s*,s:o*,s:O*}", "a", NULL, "b", NULL, "c", NULL);
+ t("[i,i,i]", 0, 1, 2);
+ t("[s,o,O]", NULL, NULL, NULL);
+ t("[**]", NULL);
+ t("[s*,o*,O*]", NULL, NULL, NULL);
+ t(" s ", "test");
+ t("[ ]");
+ t("[ i , i, i ] ", 1, 2, 3);
+ t("{\n\n1");
+ t("[}");
+ t("{]");
+ t("[");
+ t("{");
+ t("[i]a", 42);
+ t("ia", 42);
+ t("s", NULL);
+ t("+", NULL);
+ t(NULL);
+ t("{s:i}", NULL, 1);
+ t("{ {}: s }", "foo");
+ t("{ s: {}, s:[ii{} }", "foo", "bar", 12, 13);
+ t("[[[[[ [[[[[ [[[[ }]]]] ]]]] ]]]]]");
+ return 0;
+}
+
+#endif
+
+
diff --git a/src/wrap-json.h b/src/wrap-json.h
new file mode 100644
index 00000000..1e95dcf2
--- /dev/null
+++ b/src/wrap-json.h
@@ -0,0 +1,29 @@
+/*
+ Copyright (C) 2016, 2017 "IoT.bzh"
+
+ author: José Bollo <jose.bollo@iot.bzh>
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+#pragma once
+
+#include <stdarg.h>
+#include <json-c/json.h>
+
+extern int wrap_json_pack_error_position(int rc);
+extern int wrap_json_pack_error_code(int rc);
+extern const char *wrap_json_pack_error_string(int rc);
+extern int wrap_json_vpack(struct json_object **result, const char *desc, va_list args);
+extern int wrap_json_pack(struct json_object **result, const char *desc, ...);
+