Formed in 2009, the Archive Team (not to be confused with the archive.org Archive-It Team) is a rogue archivist collective dedicated to saving copies of rapidly dying or deleted websites for the sake of history and digital heritage. The group is 100% composed of volunteers and interested parties, and has expanded into a large amount of related projects for saving online and digital history.
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| #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, ']'); | |
| } |