From: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
Add "struct json_writer" and a series of jw_ routines to compose JSON
data into a string buffer. The resulting string may then be printed by
commands wanting to support a JSON-like output format.
The json_writer is limited to correctly formatting structured data for
output. It does not attempt to build an object model of the JSON data.
We say "JSON-like" because we do not enforce the Unicode (usually UTF-8)
requirement on string fields. Internally, Git does not necessarily have
Unicode/UTF-8 data for most fields, so it is currently unclear the best
way to enforce that requirement. For example, on Linux pathnames can
contain arbitrary 8-bit character data, so a command like "status" would
not know how to encode the reported pathnames. We may want to revisit
this (or double encode such strings) in the future.
Helped-by: Eric Sunshine <sunshine@xxxxxxxxxxxxxx>
Helped-by: René Scharfe <l.s.r@xxxxxx>
Helped-by: Wink Saville <wink@xxxxxxxxxxx>
Helped-by: Ramsay Jones <ramsay@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
---
Makefile | 2 +
json-writer.c | 414 ++++++++++++++++++++++++++++++++
json-writer.h | 105 ++++++++
t/helper/test-json-writer.c | 565 ++++++++++++++++++++++++++++++++++++++++++++
t/helper/test-tool.c | 1 +
t/helper/test-tool.h | 1 +
t/t0019-json-writer.sh | 331 ++++++++++++++++++++++++++
t/t0019/parse_json.perl | 52 ++++
8 files changed, 1471 insertions(+)
create mode 100644 json-writer.c
create mode 100644 json-writer.h
create mode 100644 t/helper/test-json-writer.c
create mode 100755 t/t0019-json-writer.sh
create mode 100644 t/t0019/parse_json.perl
diff --git a/Makefile b/Makefile
index e4b503d..39ca66b 100644
--- a/Makefile
+++ b/Makefile
@@ -709,6 +709,7 @@ TEST_BUILTINS_OBJS += test-example-decorate.o
TEST_BUILTINS_OBJS += test-genrandom.o
TEST_BUILTINS_OBJS += test-hashmap.o
TEST_BUILTINS_OBJS += test-index-version.o
+TEST_BUILTINS_OBJS += test-json-writer.o
TEST_BUILTINS_OBJS += test-lazy-init-name-hash.o
TEST_BUILTINS_OBJS += test-match-trees.o
TEST_BUILTINS_OBJS += test-mergesort.o
@@ -871,6 +872,7 @@ LIB_OBJS += hashmap.o
LIB_OBJS += help.o
LIB_OBJS += hex.o
LIB_OBJS += ident.o
+LIB_OBJS += json-writer.o
LIB_OBJS += kwset.o
LIB_OBJS += levenshtein.o
LIB_OBJS += line-log.o
diff --git a/json-writer.c b/json-writer.c
new file mode 100644
index 0000000..aadb9db
--- /dev/null
+++ b/json-writer.c
@@ -0,0 +1,414 @@
+#include "cache.h"
+#include "json-writer.h"
+
+void jw_init(struct json_writer *jw)
+{
+ strbuf_init(&jw->json, 0);
+ strbuf_init(&jw->open_stack, 0);
+ jw->need_comma = 0;
+ jw->pretty = 0;
+}
+
+void jw_release(struct json_writer *jw)
+{
+ strbuf_release(&jw->json);
+ strbuf_release(&jw->open_stack);
+}
+
+/*
+ * Append JSON-quoted version of the given string to 'out'.
+ */
+static void append_quoted_string(struct strbuf *out, const char *in)
+{
+ unsigned char c;
+
+ strbuf_addch(out, '"');
+ while ((c = *in++) != '\0') {
+ if (c == '"')
+ strbuf_addstr(out, "\\\"");
+ else if (c == '\\')
+ strbuf_addstr(out, "\\\\");
+ else if (c == '\n')
+ strbuf_addstr(out, "\\n");
+ else if (c == '\r')
+ strbuf_addstr(out, "\\r");
+ else if (c == '\t')
+ strbuf_addstr(out, "\\t");
+ else if (c == '\f')
+ strbuf_addstr(out, "\\f");
+ else if (c == '\b')
+ strbuf_addstr(out, "\\b");
+ else if (c < 0x20)
+ strbuf_addf(out, "\\u%04x", c);
+ else
+ strbuf_addch(out, c);
+ }
+ strbuf_addch(out, '"');
+}
+
+static void indent_pretty(struct json_writer *jw)
+{
+ int k;
+
+ for (k = 0; k < jw->open_stack.len; k++)
+ strbuf_addstr(&jw->json, " ");
+}
+
+/*
+ * Begin an object or array (either top-level or nested within the currently
+ * open object or array).
+ */
+static void begin(struct json_writer *jw, char ch_open, int pretty)
+{
+ jw->pretty = pretty;
+
+ strbuf_addch(&jw->json, ch_open);
+
+ strbuf_addch(&jw->open_stack, ch_open);
+ jw->need_comma = 0;
+}
+
+/*
+ * Assert that the top of the open-stack is an object.
+ */
+static void assert_in_object(const struct json_writer *jw, const char *key)
+{
+ if (!jw->open_stack.len)
+ BUG("json-writer: object: missing jw_object_begin(): '%s'", key);
+ if (jw->open_stack.buf[jw->open_stack.len - 1] != '{')
+ BUG("json-writer: object: not in object: '%s'", key);
+}
+
+/*
+ * Assert that the top of the open-stack is an array.
+ */
+static void assert_in_array(const struct json_writer *jw)
+{
+ if (!jw->open_stack.len)
+ BUG("json-writer: array: missing jw_array_begin()");
+ if (jw->open_stack.buf[jw->open_stack.len - 1] != '[')
+ BUG("json-writer: array: not in array");
+}
+
+/*
+ * Add comma if we have already seen a member at this level.
+ */
+static void maybe_add_comma(struct json_writer *jw)
+{
+ if (jw->need_comma)
+ strbuf_addch(&jw->json, ',');
+ else
+ jw->need_comma = 1;
+}
+
+static void fmt_double(struct json_writer *jw, int precision,
+ double value)
+{
+ if (precision < 0) {
+ strbuf_addf(&jw->json, "%f", value);
+ } else {
+ struct strbuf fmt = STRBUF_INIT;
+ strbuf_addf(&fmt, "%%.%df", precision);
+ strbuf_addf(&jw->json, fmt.buf, value);
+ strbuf_release(&fmt);
+ }
+}
+
+static void object_common(struct json_writer *jw, const char *key)
+{
+ assert_in_object(jw, key);
+ maybe_add_comma(jw);
+
+ if (jw->pretty) {
+ strbuf_addch(&jw->json, '\n');
+ indent_pretty(jw);
+ }
+
+ append_quoted_string(&jw->json, key);
+ strbuf_addch(&jw->json, ':');
+ if (jw->pretty)
+ strbuf_addch(&jw->json, ' ');
+}
+
+static void array_common(struct json_writer *jw)
+{
+ assert_in_array(jw);
+ maybe_add_comma(jw);
+
+ if (jw->pretty) {
+ strbuf_addch(&jw->json, '\n');
+ indent_pretty(jw);
+ }
+}
+
+/*
+ * Assert that the given JSON object or JSON array has been properly
+ * terminated. (Has closing bracket.)
+ */
+static void assert_is_terminated(const struct json_writer *jw)
+{
+ if (jw->open_stack.len)
+ BUG("json-writer: object: missing jw_end(): '%s'",
+ jw->json.buf);
+}
+
+void jw_object_begin(struct json_writer *jw, int pretty)
+{
+ begin(jw, '{', pretty);
+}
+
+void jw_object_string(struct json_writer *jw, const char *key, const char *value)
+{
+ object_common(jw, key);
+ append_quoted_string(&jw->json, value);
+}
+
+void jw_object_intmax(struct json_writer *jw, const char *key, intmax_t value)
+{
+ object_common(jw, key);
+ strbuf_addf(&jw->json, "%"PRIdMAX, value);
+}
+
+void jw_object_double(struct json_writer *jw, const char *key, int precision,
+ double value)
+{
+ object_common(jw, key);
+ fmt_double(jw, precision, value);
+}
+
+void jw_object_true(struct json_writer *jw, const char *key)
+{
+ object_common(jw, key);
+ strbuf_addstr(&jw->json, "true");
+}
+
+void jw_object_false(struct json_writer *jw, const char *key)
+{
+ object_common(jw, key);
+ strbuf_addstr(&jw->json, "false");
+}
+
+void jw_object_bool(struct json_writer *jw, const char *key, int value)
+{
+ if (value)
+ jw_object_true(jw, key);
+ else
+ jw_object_false(jw, key);
+}
+
+void jw_object_null(struct json_writer *jw, const char *key)
+{
+ object_common(jw, key);
+ strbuf_addstr(&jw->json, "null");
+}
+
+static void increase_indent(struct strbuf *sb,
+ const struct json_writer *jw,
+ int indent)
+{
+ int k;
+
+ strbuf_reset(sb);
+ for (k = 0; k < jw->json.len; k++) {
+ char ch = jw->json.buf[k];
+ strbuf_addch(sb, ch);
+ if (ch == '\n')
+ strbuf_addchars(sb, ' ', indent);
+ }
+}
+
+static void kill_indent(struct strbuf *sb,
+ const struct json_writer *jw)
+{
+ int k;
+ int eat_it = 0;
+
+ strbuf_reset(sb);
+ for (k = 0; k < jw->json.len; k++) {
+ char ch = jw->json.buf[k];
+ if (eat_it && ch == ' ')
+ continue;
+ if (ch == '\n') {
+ eat_it = 1;
+ continue;
+ }
+ eat_it = 0;
+ strbuf_addch(sb, ch);
+ }
+}
+
+static void append_sub_jw(struct json_writer *jw,
+ const struct json_writer *value)
+{
+ /*
+ * If both are pretty, increase the indentation of the sub_jw
+ * to better fit under the super.
+ *
+ * If the super is pretty, but the sub_jw is compact, leave the
+ * sub_jw compact. (We don't want to parse and rebuild the sub_jw
+ * for this debug-ish feature.)
+ *
+ * If the super is compact, and the sub_jw is pretty, convert
+ * the sub_jw to compact.
+ *
+ * If both are compact, keep the sub_jw compact.
+ */
+ if (jw->pretty && jw->open_stack.len && value->pretty) {
+ struct strbuf sb = STRBUF_INIT;
+ increase_indent(&sb, value, jw->open_stack.len * 2);
+ strbuf_addbuf(&jw->json, &sb);
+ strbuf_release(&sb);
+ return;
+ }
+ if (!jw->pretty && value->pretty) {
+ struct strbuf sb = STRBUF_INIT;
+ kill_indent(&sb, value);
+ strbuf_addbuf(&jw->json, &sb);
+ strbuf_release(&sb);
+ return;
+ }
+
+ strbuf_addbuf(&jw->json, &value->json);
+}
+
+/*
+ * Append existing (properly terminated) JSON sub-data (object or array)
+ * as-is onto the given JSON data.
+ */
+void jw_object_sub_jw(struct json_writer *jw, const char *key,
+ const struct json_writer *value)
+{
+ assert_is_terminated(value);
+
+ object_common(jw, key);
+ append_sub_jw(jw, value);
+}
+
+void jw_object_inline_begin_object(struct json_writer *jw, const char *key)
+{
+ object_common(jw, key);
+
+ jw_object_begin(jw, jw->pretty);
+}
+
+void jw_object_inline_begin_array(struct json_writer *jw, const char *key)
+{
+ object_common(jw, key);
+
+ jw_array_begin(jw, jw->pretty);
+}
+
+void jw_array_begin(struct json_writer *jw, int pretty)
+{
+ begin(jw, '[', pretty);
+}
+
+void jw_array_string(struct json_writer *jw, const char *value)
+{
+ array_common(jw);
+ append_quoted_string(&jw->json, value);
+}
+
+void jw_array_intmax(struct json_writer *jw, intmax_t value)
+{
+ array_common(jw);
+ strbuf_addf(&jw->json, "%"PRIdMAX, value);
+}
+
+void jw_array_double(struct json_writer *jw, int precision, double value)
+{
+ array_common(jw);
+ fmt_double(jw, precision, value);
+}
+
+void jw_array_true(struct json_writer *jw)
+{
+ array_common(jw);
+ strbuf_addstr(&jw->json, "true");
+}
+
+void jw_array_false(struct json_writer *jw)
+{
+ array_common(jw);
+ strbuf_addstr(&jw->json, "false");
+}
+
+void jw_array_bool(struct json_writer *jw, int value)
+{
+ if (value)
+ jw_array_true(jw);
+ else
+ jw_array_false(jw);
+}
+
+void jw_array_null(struct json_writer *jw)
+{
+ array_common(jw);
+ strbuf_addstr(&jw->json, "null");
+}
+
+void jw_array_sub_jw(struct json_writer *jw, const struct json_writer *value)
+{
+ assert_is_terminated(value);
+
+ array_common(jw);
+ append_sub_jw(jw, value);
+}
+
+void jw_array_argc_argv(struct json_writer *jw, int argc, const char **argv)
+{
+ int k;
+
+ for (k = 0; k < argc; k++)
+ jw_array_string(jw, argv[k]);
+}
+
+void jw_array_argv(struct json_writer *jw, const char **argv)
+{
+ while (*argv)
+ jw_array_string(jw, *argv++);
+}
+
+void jw_array_inline_begin_object(struct json_writer *jw)
+{
+ array_common(jw);
+
+ jw_object_begin(jw, jw->pretty);
+}
+
+void jw_array_inline_begin_array(struct json_writer *jw)
+{
+ array_common(jw);
+
+ jw_array_begin(jw, jw->pretty);
+}
+
+int jw_is_terminated(const struct json_writer *jw)
+{
+ return !jw->open_stack.len;
+}
+
+void jw_end(struct json_writer *jw)
+{
+ char ch_open;
+ int len;
+
+ if (!jw->open_stack.len)
+ BUG("json-writer: too many jw_end(): '%s'", jw->json.buf);
+
+ len = jw->open_stack.len - 1;
+ ch_open = jw->open_stack.buf[len];
+
+ strbuf_setlen(&jw->open_stack, len);
+ jw->need_comma = 1;
+
+ if (jw->pretty) {
+ strbuf_addch(&jw->json, '\n');
+ indent_pretty(jw);
+ }
+
+ if (ch_open == '{')
+ strbuf_addch(&jw->json, '}');
+ else
+ strbuf_addch(&jw->json, ']');
+}
diff --git a/json-writer.h b/json-writer.h
new file mode 100644
index 0000000..fc18acc
--- /dev/null
+++ b/json-writer.h
@@ -0,0 +1,105 @@
+#ifndef JSON_WRITER_H
+#define JSON_WRITER_H
+
+/*
+ * JSON data structures are defined at:
+ * [1] http://www.ietf.org/rfc/rfc7159.txt
+ * [2] http://json.org/
+ *
+ * The JSON-writer API allows one to build JSON data structures using a
+ * simple wrapper around a "struct strbuf" buffer. It is intended as a
+ * simple API to build output strings; it is not intended to be a general
+ * object model for JSON data. In particular, it does not re-order keys
+ * in an object (dictionary), it does not de-dup keys in an object, and
+ * it does not allow lookup or parsing of JSON data.
+ *
+ * All string values (both keys and string r-values) are properly quoted
+ * and escaped if they contain special characters.
+ *
+ * These routines create compact JSON data (with no unnecessary whitespace,
+ * newlines, or indenting). If you get an unexpected response, verify
+ * that you're not expecting a pretty JSON string.
+ *
+ * Both "JSON objects" (aka sets of k/v pairs) and "JSON array" can be
+ * constructed using a 'begin append* end' model.
+ *
+ * Nested objects and arrays can either be constructed bottom up (by
+ * creating sub object/arrays first and appending them to the super
+ * object/array) -or- by building them inline in one pass. This is a
+ * personal style and/or data shape choice.
+ *
+ * See t/helper/test-json-writer.c for various usage examples.
+ *
+ * LIMITATIONS:
+ * ============
+ *
+ * The JSON specification [1,2] defines string values as Unicode data
+ * and probably UTF-8 encoded. The current json-writer API does not
+ * enforce this and will write any string as received. However, it will
+ * properly quote and backslash-escape them as necessary. It is up to
+ * the caller to UTF-8 encode their strings *before* passing them to this
+ * API. This layer should not have to try to guess the encoding or locale
+ * of the given strings.
+ */
+
+struct json_writer
+{
+ /*
+ * Buffer of the in-progress JSON currently being composed.
+ */
+ struct strbuf json;
+
+ /*
+ * Simple stack of the currently open array and object forms.
+ * This is a string of '{' and '[' characters indicating the
+ * currently unterminated forms. This is used to ensure the
+ * properly closing character is used when popping a level and
+ * to know when the JSON is completely closed.
+ */
+ struct strbuf open_stack;
+
+ unsigned int need_comma:1;
+ unsigned int pretty:1;
+};
+
+#define JSON_WRITER_INIT { STRBUF_INIT, STRBUF_INIT, 0, 0 }
+
+void jw_init(struct json_writer *jw);
+void jw_release(struct json_writer *jw);
+
+void jw_object_begin(struct json_writer *jw, int pretty);
+void jw_array_begin(struct json_writer *jw, int pretty);
+
+void jw_object_string(struct json_writer *jw, const char *key,
+ const char *value);
+void jw_object_intmax(struct json_writer *jw, const char *key, intmax_t value);
+void jw_object_double(struct json_writer *jw, const char *key, int precision,
+ double value);
+void jw_object_true(struct json_writer *jw, const char *key);
+void jw_object_false(struct json_writer *jw, const char *key);
+void jw_object_bool(struct json_writer *jw, const char *key, int value);
+void jw_object_null(struct json_writer *jw, const char *key);
+void jw_object_sub_jw(struct json_writer *jw, const char *key,
+ const struct json_writer *value);
+
+void jw_object_inline_begin_object(struct json_writer *jw, const char *key);
+void jw_object_inline_begin_array(struct json_writer *jw, const char *key);
+
+void jw_array_string(struct json_writer *jw, const char *value);
+void jw_array_intmax(struct json_writer *jw, intmax_t value);
+void jw_array_double(struct json_writer *jw, int precision, double value);
+void jw_array_true(struct json_writer *jw);
+void jw_array_false(struct json_writer *jw);
+void jw_array_bool(struct json_writer *jw, int value);
+void jw_array_null(struct json_writer *jw);
+void jw_array_sub_jw(struct json_writer *jw, const struct json_writer *value);
+void jw_array_argc_argv(struct json_writer *jw, int argc, const char **argv);
+void jw_array_argv(struct json_writer *jw, const char **argv);
+
+void jw_array_inline_begin_object(struct json_writer *jw);
+void jw_array_inline_begin_array(struct json_writer *jw);
+
+int jw_is_terminated(const struct json_writer *jw);
+void jw_end(struct json_writer *jw);
+
+#endif /* JSON_WRITER_H */
diff --git a/t/helper/test-json-writer.c b/t/helper/test-json-writer.c
new file mode 100644
index 0000000..37c4525
--- /dev/null
+++ b/t/helper/test-json-writer.c
@@ -0,0 +1,565 @@
+#include "test-tool.h"
+#include "cache.h"
+#include "json-writer.h"
+
+static const char *expect_obj1 = "{\"a\":\"abc\",\"b\":42,\"c\":true}";
+static const char *expect_obj2 = "{\"a\":-1,\"b\":2147483647,\"c\":0}";
+static const char *expect_obj3 = "{\"a\":0,\"b\":4294967295,\"c\":9223372036854775807}";
+static const char *expect_obj4 = "{\"t\":true,\"f\":false,\"n\":null}";
+static const char *expect_obj5 = "{\"abc\\tdef\":\"abc\\\\def\"}";
+static const char *expect_obj6 = "{\"a\":3.14}";
+
+static const char *pretty_obj1 = ("{\n"
+ " \"a\": \"abc\",\n"
+ " \"b\": 42,\n"
+ " \"c\": true\n"
+ "}");
+static const char *pretty_obj2 = ("{\n"
+ " \"a\": -1,\n"
+ " \"b\": 2147483647,\n"
+ " \"c\": 0\n"
+ "}");
+static const char *pretty_obj3 = ("{\n"
+ " \"a\": 0,\n"
+ " \"b\": 4294967295,\n"
+ " \"c\": 9223372036854775807\n"
+ "}");
+static const char *pretty_obj4 = ("{\n"
+ " \"t\": true,\n"
+ " \"f\": false,\n"
+ " \"n\": null\n"
+ "}");
+
+static struct json_writer obj1 = JSON_WRITER_INIT;
+static struct json_writer obj2 = JSON_WRITER_INIT;
+static struct json_writer obj3 = JSON_WRITER_INIT;
+static struct json_writer obj4 = JSON_WRITER_INIT;
+static struct json_writer obj5 = JSON_WRITER_INIT;
+static struct json_writer obj6 = JSON_WRITER_INIT;
+
+static void make_obj1(int pretty)
+{
+ jw_object_begin(&obj1, pretty);
+ {
+ jw_object_string(&obj1, "a", "abc");
+ jw_object_intmax(&obj1, "b", 42);
+ jw_object_true(&obj1, "c");
+ }
+ jw_end(&obj1);
+}
+
+static void make_obj2(int pretty)
+{
+ jw_object_begin(&obj2, pretty);
+ {
+ jw_object_intmax(&obj2, "a", -1);
+ jw_object_intmax(&obj2, "b", 0x7fffffff);
+ jw_object_intmax(&obj2, "c", 0);
+ }
+ jw_end(&obj2);
+}
+
+static void make_obj3(int pretty)
+{
+ jw_object_begin(&obj3, pretty);
+ {
+ jw_object_intmax(&obj3, "a", 0);
+ jw_object_intmax(&obj3, "b", 0xffffffff);
+ jw_object_intmax(&obj3, "c", 0x7fffffffffffffffULL);
+ }
+ jw_end(&obj3);
+}
+
+static void make_obj4(int pretty)
+{
+ jw_object_begin(&obj4, pretty);
+ {
+ jw_object_true(&obj4, "t");
+ jw_object_false(&obj4, "f");
+ jw_object_null(&obj4, "n");
+ }
+ jw_end(&obj4);
+}
+
+static void make_obj5(int pretty)
+{
+ jw_object_begin(&obj5, pretty);
+ {
+ jw_object_string(&obj5, "abc" "\x09" "def", "abc" "\\" "def");
+ }
+ jw_end(&obj5);
+}
+
+static void make_obj6(int pretty)
+{
+ jw_object_begin(&obj6, pretty);
+ {
+ jw_object_double(&obj6, "a", 2, 3.14159);
+ }
+ jw_end(&obj6);
+}
+
+static const char *expect_arr1 = "[\"abc\",42,true]";
+static const char *expect_arr2 = "[-1,2147483647,0]";
+static const char *expect_arr3 = "[0,4294967295,9223372036854775807]";
+static const char *expect_arr4 = "[true,false,null]";
+
+static const char *pretty_arr1 = ("[\n"
+ " \"abc\",\n"
+ " 42,\n"
+ " true\n"
+ "]");
+static const char *pretty_arr2 = ("[\n"
+ " -1,\n"
+ " 2147483647,\n"
+ " 0\n"
+ "]");
+static const char *pretty_arr3 = ("[\n"
+ " 0,\n"
+ " 4294967295,\n"
+ " 9223372036854775807\n"
+ "]");
+static const char *pretty_arr4 = ("[\n"
+ " true,\n"
+ " false,\n"
+ " null\n"
+ "]");
+
+static struct json_writer arr1 = JSON_WRITER_INIT;
+static struct json_writer arr2 = JSON_WRITER_INIT;
+static struct json_writer arr3 = JSON_WRITER_INIT;
+static struct json_writer arr4 = JSON_WRITER_INIT;
+
+static void make_arr1(int pretty)
+{
+ jw_array_begin(&arr1, pretty);
+ {
+ jw_array_string(&arr1, "abc");
+ jw_array_intmax(&arr1, 42);
+ jw_array_true(&arr1);
+ }
+ jw_end(&arr1);
+}
+
+static void make_arr2(int pretty)
+{
+ jw_array_begin(&arr2, pretty);
+ {
+ jw_array_intmax(&arr2, -1);
+ jw_array_intmax(&arr2, 0x7fffffff);
+ jw_array_intmax(&arr2, 0);
+ }
+ jw_end(&arr2);
+}
+
+static void make_arr3(int pretty)
+{
+ jw_array_begin(&arr3, pretty);
+ {
+ jw_array_intmax(&arr3, 0);
+ jw_array_intmax(&arr3, 0xffffffff);
+ jw_array_intmax(&arr3, 0x7fffffffffffffffULL);
+ }
+ jw_end(&arr3);
+}
+
+static void make_arr4(int pretty)
+{
+ jw_array_begin(&arr4, pretty);
+ {
+ jw_array_true(&arr4);
+ jw_array_false(&arr4);
+ jw_array_null(&arr4);
+ }
+ jw_end(&arr4);
+}
+
+static char *expect_nest1 =
+ "{\"obj1\":{\"a\":\"abc\",\"b\":42,\"c\":true},\"arr1\":[\"abc\",42,true]}";
+
+static struct json_writer nest1 = JSON_WRITER_INIT;
+
+static void make_nest1(int pretty)
+{
+ jw_object_begin(&nest1, pretty);
+ {
+ jw_object_sub_jw(&nest1, "obj1", &obj1);
+ jw_object_sub_jw(&nest1, "arr1", &arr1);
+ }
+ jw_end(&nest1);
+}
+
+static char *expect_inline1 =
+ "{\"obj1\":{\"a\":\"abc\",\"b\":42,\"c\":true},\"arr1\":[\"abc\",42,true]}";
+
+static char *pretty_inline1 =
+ ("{\n"
+ " \"obj1\": {\n"
+ " \"a\": \"abc\",\n"
+ " \"b\": 42,\n"
+ " \"c\": true\n"
+ " },\n"
+ " \"arr1\": [\n"
+ " \"abc\",\n"
+ " 42,\n"
+ " true\n"
+ " ]\n"
+ "}");
+
+static struct json_writer inline1 = JSON_WRITER_INIT;
+
+static void make_inline1(int pretty)
+{
+ jw_object_begin(&inline1, pretty);
+ {
+ jw_object_inline_begin_object(&inline1, "obj1");
+ {
+ jw_object_string(&inline1, "a", "abc");
+ jw_object_intmax(&inline1, "b", 42);
+ jw_object_true(&inline1, "c");
+ }
+ jw_end(&inline1);
+ jw_object_inline_begin_array(&inline1, "arr1");
+ {
+ jw_array_string(&inline1, "abc");
+ jw_array_intmax(&inline1, 42);
+ jw_array_true(&inline1);
+ }
+ jw_end(&inline1);
+ }
+ jw_end(&inline1);
+}
+
+static char *expect_inline2 =
+ "[[1,2],[3,4],{\"a\":\"abc\"}]";
+
+static char *pretty_inline2 =
+ ("[\n"
+ " [\n"
+ " 1,\n"
+ " 2\n"
+ " ],\n"
+ " [\n"
+ " 3,\n"
+ " 4\n"
+ " ],\n"
+ " {\n"
+ " \"a\": \"abc\"\n"
+ " }\n"
+ "]");
+
+static struct json_writer inline2 = JSON_WRITER_INIT;
+
+static void make_inline2(int pretty)
+{
+ jw_array_begin(&inline2, pretty);
+ {
+ jw_array_inline_begin_array(&inline2);
+ {
+ jw_array_intmax(&inline2, 1);
+ jw_array_intmax(&inline2, 2);
+ }
+ jw_end(&inline2);
+ jw_array_inline_begin_array(&inline2);
+ {
+ jw_array_intmax(&inline2, 3);
+ jw_array_intmax(&inline2, 4);
+ }
+ jw_end(&inline2);
+ jw_array_inline_begin_object(&inline2);
+ {
+ jw_object_string(&inline2, "a", "abc");
+ }
+ jw_end(&inline2);
+ }
+ jw_end(&inline2);
+}
+
+/*
+ * When super is compact, we expect subs to be compacted (even if originally
+ * pretty).
+ */
+static const char *expect_mixed1 =
+ ("{\"obj1\":{\"a\":\"abc\",\"b\":42,\"c\":true},"
+ "\"arr1\":[\"abc\",42,true]}");
+
+/*
+ * When super is pretty, a compact sub (obj1) is kept compact and a pretty
+ * sub (arr1) is re-indented.
+ */
+static const char *pretty_mixed1 =
+ ("{\n"
+ " \"obj1\": {\"a\":\"abc\",\"b\":42,\"c\":true},\n"
+ " \"arr1\": [\n"
+ " \"abc\",\n"
+ " 42,\n"
+ " true\n"
+ " ]\n"
+ "}");
+
+static struct json_writer mixed1 = JSON_WRITER_INIT;
+
+static void make_mixed1(int pretty)
+{
+ jw_init(&obj1);
+ jw_init(&arr1);
+
+ make_obj1(0); /* obj1 is compact */
+ make_arr1(1); /* arr1 is pretty */
+
+ jw_object_begin(&mixed1, pretty);
+ {
+ jw_object_sub_jw(&mixed1, "obj1", &obj1);
+ jw_object_sub_jw(&mixed1, "arr1", &arr1);
+ }
+ jw_end(&mixed1);
+}
+
+static void cmp(const char *test, const struct json_writer *jw, const char *exp)
+{
+ if (!strcmp(jw->json.buf, exp))
+ return;
+
+ printf("error[%s]: observed '%s' expected '%s'\n",
+ test, jw->json.buf, exp);
+ exit(1);
+}
+
+#define t(v) do { make_##v(0); cmp(#v, &v, expect_##v); } while (0)
+#define p(v) do { make_##v(1); cmp(#v, &v, pretty_##v); } while (0)
+
+/*
+ * Run some basic regression tests with some known patterns.
+ * These tests also demonstrate how to use the jw_ API.
+ */
+static int unit_tests(void)
+{
+ /* comptact (canonical) forms */
+ t(obj1);
+ t(obj2);
+ t(obj3);
+ t(obj4);
+ t(obj5);
+ t(obj6);
+
+ t(arr1);
+ t(arr2);
+ t(arr3);
+ t(arr4);
+
+ t(nest1);
+
+ t(inline1);
+ t(inline2);
+
+ jw_init(&obj1);
+ jw_init(&obj2);
+ jw_init(&obj3);
+ jw_init(&obj4);
+
+ jw_init(&arr1);
+ jw_init(&arr2);
+ jw_init(&arr3);
+ jw_init(&arr4);
+
+ jw_init(&inline1);
+ jw_init(&inline2);
+
+ /* pretty forms */
+ p(obj1);
+ p(obj2);
+ p(obj3);
+ p(obj4);
+
+ p(arr1);
+ p(arr2);
+ p(arr3);
+ p(arr4);
+
+ p(inline1);
+ p(inline2);
+
+ /* mixed forms */
+ t(mixed1);
+ jw_init(&mixed1);
+ p(mixed1);
+
+ return 0;
+}
+
+static void get_s(int line_nr, char **s_in)
+{
+ *s_in = strtok(NULL, " ");
+ if (!*s_in)
+ die("line[%d]: expected: <s>", line_nr);
+}
+
+static void get_i(int line_nr, intmax_t *s_in)
+{
+ char *s;
+ char *endptr;
+
+ get_s(line_nr, &s);
+
+ *s_in = strtol(s, &endptr, 10);
+ if (*endptr || errno == ERANGE)
+ die("line[%d]: invalid integer value", line_nr);
+}
+
+static void get_d(int line_nr, double *s_in)
+{
+ char *s;
+ char *endptr;
+
+ get_s(line_nr, &s);
+
+ *s_in = strtod(s, &endptr);
+ if (*endptr || errno == ERANGE)
+ die("line[%d]: invalid float value", line_nr);
+}
+
+static int pretty;
+
+#define MAX_LINE_LENGTH (64 * 1024)
+
+static char *get_trimmed_line(char *buf, int buf_size)
+{
+ int len;
+
+ if (!fgets(buf, buf_size, stdin))
+ return NULL;
+
+ len = strlen(buf);
+ while (len > 0) {
+ char c = buf[len - 1];
+ if (c == '\n' || c == '\r' || c == ' ' || c == '\t')
+ buf[--len] = 0;
+ else
+ break;
+ }
+
+ while (*buf == ' ' || *buf == '\t')
+ buf++;
+
+ return buf;
+}
+
+static int scripted(void)
+{
+ struct json_writer jw = JSON_WRITER_INIT;
+ char buf[MAX_LINE_LENGTH];
+ char *line;
+ int line_nr = 0;
+
+ line = get_trimmed_line(buf, MAX_LINE_LENGTH);
+ if (!line)
+ return 0;
+
+ if (!strcmp(line, "object"))
+ jw_object_begin(&jw, pretty);
+ else if (!strcmp(line, "array"))
+ jw_array_begin(&jw, pretty);
+ else
+ die("expected first line to be 'object' or 'array'");
+
+ while ((line = get_trimmed_line(buf, MAX_LINE_LENGTH)) != NULL) {
+ char *verb;
+ char *key;
+ char *s_value;
+ intmax_t i_value;
+ double d_value;
+
+ line_nr++;
+
+ verb = strtok(line, " ");
+
+ if (!strcmp(verb, "end")) {
+ jw_end(&jw);
+ }
+ else if (!strcmp(verb, "object-string")) {
+ get_s(line_nr, &key);
+ get_s(line_nr, &s_value);
+ jw_object_string(&jw, key, s_value);
+ }
+ else if (!strcmp(verb, "object-int")) {
+ get_s(line_nr, &key);
+ get_i(line_nr, &i_value);
+ jw_object_intmax(&jw, key, i_value);
+ }
+ else if (!strcmp(verb, "object-double")) {
+ get_s(line_nr, &key);
+ get_i(line_nr, &i_value);
+ get_d(line_nr, &d_value);
+ jw_object_double(&jw, key, i_value, d_value);
+ }
+ else if (!strcmp(verb, "object-true")) {
+ get_s(line_nr, &key);
+ jw_object_true(&jw, key);
+ }
+ else if (!strcmp(verb, "object-false")) {
+ get_s(line_nr, &key);
+ jw_object_false(&jw, key);
+ }
+ else if (!strcmp(verb, "object-null")) {
+ get_s(line_nr, &key);
+ jw_object_null(&jw, key);
+ }
+ else if (!strcmp(verb, "object-object")) {
+ get_s(line_nr, &key);
+ jw_object_inline_begin_object(&jw, key);
+ }
+ else if (!strcmp(verb, "object-array")) {
+ get_s(line_nr, &key);
+ jw_object_inline_begin_array(&jw, key);
+ }
+ else if (!strcmp(verb, "array-string")) {
+ get_s(line_nr, &s_value);
+ jw_array_string(&jw, s_value);
+ }
+ else if (!strcmp(verb, "array-int")) {
+ get_i(line_nr, &i_value);
+ jw_array_intmax(&jw, i_value);
+ }
+ else if (!strcmp(verb, "array-double")) {
+ get_i(line_nr, &i_value);
+ get_d(line_nr, &d_value);
+ jw_array_double(&jw, i_value, d_value);
+ }
+ else if (!strcmp(verb, "array-true"))
+ jw_array_true(&jw);
+ else if (!strcmp(verb, "array-false"))
+ jw_array_false(&jw);
+ else if (!strcmp(verb, "array-null"))
+ jw_array_null(&jw);
+ else if (!strcmp(verb, "array-object"))
+ jw_array_inline_begin_object(&jw);
+ else if (!strcmp(verb, "array-array"))
+ jw_array_inline_begin_array(&jw);
+ else
+ die("unrecognized token: '%s'", verb);
+ }
+
+ if (!jw_is_terminated(&jw))
+ die("json not terminated: '%s'", jw.json.buf);
+
+ printf("%s\n", jw.json.buf);
+
+ strbuf_release(&jw.json);
+ return 0;
+}
+
+int cmd__json_writer(int argc, const char **argv)
+{
+ argc--; /* skip over "json-writer" arg */
+ argv++;
+
+ if (argc > 0 && argv[0][0] == '-') {
+ if (!strcmp(argv[0], "-u") || !strcmp(argv[0], "--unit"))
+ return unit_tests();
+
+ if (!strcmp(argv[0], "-p") || !strcmp(argv[0], "--pretty"))
+ pretty = 1;
+ }
+
+ return scripted();
+}
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index 805a45d..707499e 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -19,6 +19,7 @@ static struct test_cmd cmds[] = {
{ "genrandom", cmd__genrandom },
{ "hashmap", cmd__hashmap },
{ "index-version", cmd__index_version },
+ { "json-writer", cmd__json_writer },
{ "lazy-init-name-hash", cmd__lazy_init_name_hash },
{ "match-trees", cmd__match_trees },
{ "mergesort", cmd__mergesort },
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index 7116ddf..a058c31 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -13,6 +13,7 @@ int cmd__example_decorate(int argc, const char **argv);
int cmd__genrandom(int argc, const char **argv);
int cmd__hashmap(int argc, const char **argv);
int cmd__index_version(int argc, const char **argv);
+int cmd__json_writer(int argc, const char **argv);
int cmd__lazy_init_name_hash(int argc, const char **argv);
int cmd__match_trees(int argc, const char **argv);
int cmd__mergesort(int argc, const char **argv);
diff --git a/t/t0019-json-writer.sh b/t/t0019-json-writer.sh
new file mode 100755
index 0000000..3b0c336
--- /dev/null
+++ b/t/t0019-json-writer.sh
@@ -0,0 +1,331 @@
+#!/bin/sh
+
+test_description='test json-writer JSON generation'
+. ./test-lib.sh
+
+test_expect_success 'unit test of json-writer routines' '
+ test-tool json-writer -u
+'
+
+test_expect_success 'trivial object' '
+ cat >expect <<-\EOF &&
+ {}
+ EOF
+ cat >input <<-\EOF &&
+ object
+ end
+ EOF
+ test-tool json-writer <input >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'trivial array' '
+ cat >expect <<-\EOF &&
+ []
+ EOF
+ cat >input <<-\EOF &&
+ array
+ end
+ EOF
+ test-tool json-writer <input >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'simple object' '
+ cat >expect <<-\EOF &&
+ {"a":"abc","b":42,"c":3.14,"d":true,"e":false,"f":null}
+ EOF
+ cat >input <<-\EOF &&
+ object
+ object-string a abc
+ object-int b 42
+ object-double c 2 3.140
+ object-true d
+ object-false e
+ object-null f
+ end
+ EOF
+ test-tool json-writer <input >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'simple array' '
+ cat >expect <<-\EOF &&
+ ["abc",42,3.14,true,false,null]
+ EOF
+ cat >input <<-\EOF &&
+ array
+ array-string abc
+ array-int 42
+ array-double 2 3.140
+ array-true
+ array-false
+ array-null
+ end
+ EOF
+ test-tool json-writer <input >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'escape quoting string' '
+ cat >expect <<-\EOF &&
+ {"a":"abc\\def"}
+ EOF
+ cat >input <<-\EOF &&
+ object
+ object-string a abc\def
+ end
+ EOF
+ test-tool json-writer <input >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'escape quoting string 2' '
+ cat >expect <<-\EOF &&
+ {"a":"abc\"def"}
+ EOF
+ cat >input <<-\EOF &&
+ object
+ object-string a abc"def
+ end
+ EOF
+ test-tool json-writer <input >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'nested inline object' '
+ cat >expect <<-\EOF &&
+ {"a":"abc","b":42,"sub1":{"c":3.14,"d":true,"sub2":{"e":false,"f":null}}}
+ EOF
+ cat >input <<-\EOF &&
+ object
+ object-string a abc
+ object-int b 42
+ object-object sub1
+ object-double c 2 3.140
+ object-true d
+ object-object sub2
+ object-false e
+ object-null f
+ end
+ end
+ end
+ EOF
+ test-tool json-writer <input >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'nested inline array' '
+ cat >expect <<-\EOF &&
+ ["abc",42,[3.14,true,[false,null]]]
+ EOF
+ cat >input <<-\EOF &&
+ array
+ array-string abc
+ array-int 42
+ array-array
+ array-double 2 3.140
+ array-true
+ array-array
+ array-false
+ array-null
+ end
+ end
+ end
+ EOF
+ test-tool json-writer <input >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'nested inline object and array' '
+ cat >expect <<-\EOF &&
+ {"a":"abc","b":42,"sub1":{"c":3.14,"d":true,"sub2":[false,null]}}
+ EOF
+ cat >input <<-\EOF &&
+ object
+ object-string a abc
+ object-int b 42
+ object-object sub1
+ object-double c 2 3.140
+ object-true d
+ object-array sub2
+ array-false
+ array-null
+ end
+ end
+ end
+ EOF
+ test-tool json-writer <input >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'nested inline object and array 2' '
+ cat >expect <<-\EOF &&
+ {"a":"abc","b":42,"sub1":{"c":3.14,"d":true,"sub2":[false,{"g":0,"h":1},null]}}
+ EOF
+ cat >input <<-\EOF &&
+ object
+ object-string a abc
+ object-int b 42
+ object-object sub1
+ object-double c 2 3.140
+ object-true d
+ object-array sub2
+ array-false
+ array-object
+ object-int g 0
+ object-int h 1
+ end
+ array-null
+ end
+ end
+ end
+ EOF
+ test-tool json-writer <input >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'pretty nested inline object and array 2' '
+ sed -e "s/^|//" >expect <<-\EOF &&
+ |{
+ | "a": "abc",
+ | "b": 42,
+ | "sub1": {
+ | "c": 3.14,
+ | "d": true,
+ | "sub2": [
+ | false,
+ | {
+ | "g": 0,
+ | "h": 1
+ | },
+ | null
+ | ]
+ | }
+ |}
+ EOF
+ cat >input <<-\EOF &&
+ object
+ object-string a abc
+ object-int b 42
+ object-object sub1
+ object-double c 2 3.140
+ object-true d
+ object-array sub2
+ array-false
+ array-object
+ object-int g 0
+ object-int h 1
+ end
+ array-null
+ end
+ end
+ end
+ EOF
+ test-tool json-writer -p <input >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'inline object with no members' '
+ cat >expect <<-\EOF &&
+ {"a":"abc","empty":{},"b":42}
+ EOF
+ cat >input <<-\EOF &&
+ object
+ object-string a abc
+ object-object empty
+ end
+ object-int b 42
+ end
+ EOF
+ test-tool json-writer <input >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'inline array with no members' '
+ cat >expect <<-\EOF &&
+ {"a":"abc","empty":[],"b":42}
+ EOF
+ cat >input <<-\EOF &&
+ object
+ object-string a abc
+ object-array empty
+ end
+ object-int b 42
+ end
+ EOF
+ test-tool json-writer <input >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'larger empty example' '
+ cat >expect <<-\EOF &&
+ {"a":"abc","empty":[{},{},{},[],{}],"b":42}
+ EOF
+ cat >input <<-\EOF &&
+ object
+ object-string a abc
+ object-array empty
+ array-object
+ end
+ array-object
+ end
+ array-object
+ end
+ array-array
+ end
+ array-object
+ end
+ end
+ object-int b 42
+ end
+ EOF
+ test-tool json-writer <input >actual &&
+ test_cmp expect actual
+'
+
+test_lazy_prereq PERLJSON '
+ perl -MJSON -e "exit 0"
+'
+
+# As a sanity check, ask Perl to parse our generated JSON and recursively
+# dump the resulting data in sorted order. Confirm that that matches our
+# expectations.
+test_expect_success PERLJSON 'parse JSON using Perl' '
+ cat >expect <<-\EOF &&
+ row[0].a abc
+ row[0].b 42
+ row[0].sub1 hash
+ row[0].sub1.c 3.14
+ row[0].sub1.d 1
+ row[0].sub1.sub2 array
+ row[0].sub1.sub2[0] 0
+ row[0].sub1.sub2[1] hash
+ row[0].sub1.sub2[1].g 0
+ row[0].sub1.sub2[1].h 1
+ row[0].sub1.sub2[2] null
+ EOF
+ cat >input <<-\EOF &&
+ object
+ object-string a abc
+ object-int b 42
+ object-object sub1
+ object-double c 2 3.140
+ object-true d
+ object-array sub2
+ array-false
+ array-object
+ object-int g 0
+ object-int h 1
+ end
+ array-null
+ end
+ end
+ end
+ EOF
+ test-tool json-writer <input >output.json &&
+ perl "$TEST_DIRECTORY"/t0019/parse_json.perl <output.json >actual &&
+ test_cmp expect actual
+'
+
+test_done
diff --git a/t/t0019/parse_json.perl b/t/t0019/parse_json.perl
new file mode 100644
index 0000000..ca4e5bf
--- /dev/null
+++ b/t/t0019/parse_json.perl
@@ -0,0 +1,52 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+use JSON;
+
+sub dump_array {
+ my ($label_in, $ary_ref) = @_;
+ my @ary = @$ary_ref;
+
+ for ( my $i = 0; $i <= $#{ $ary_ref }; $i++ )
+ {
+ my $label = "$label_in\[$i\]";
+ dump_item($label, $ary[$i]);
+ }
+}
+
+sub dump_hash {
+ my ($label_in, $obj_ref) = @_;
+ my %obj = %$obj_ref;
+
+ foreach my $k (sort keys %obj) {
+ my $label = (length($label_in) > 0) ? "$label_in.$k" : "$k";
+ my $value = $obj{$k};
+
+ dump_item($label, $value);
+ }
+}
+
+sub dump_item {
+ my ($label_in, $value) = @_;
+ if (ref($value) eq 'ARRAY') {
+ print "$label_in array\n";
+ dump_array($label_in, $value);
+ } elsif (ref($value) eq 'HASH') {
+ print "$label_in hash\n";
+ dump_hash($label_in, $value);
+ } elsif (defined $value) {
+ print "$label_in $value\n";
+ } else {
+ print "$label_in null\n";
+ }
+}
+
+my $row = 0;
+while (<>) {
+ my $data = decode_json( $_ );
+ my $label = "row[$row]";
+
+ dump_hash($label, $data);
+ $row++;
+}
+
--
2.9.3
