From 3122085a792676e5104e0407be35db38c5964eea Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 21 Jun 2019 17:19:25 +0200 Subject: [PATCH] btrfs-progs: output formatter infrastructure Add structures and API for unified output definition and multiple formatting backends. Currently there's plain text and json. The format of each row is defined in struct rowspec, selected using a key and formatted according to the type. There are extended types for eg. UUID or pretty size, while direct printf format specifiers work too. Due to different nature of the outputs, the context structure members are not always used. * text output mostly uses indentation and formats the name to a given width * json output tracks nesting depth and keeps stack of previous groups (list or array) and how many member have been printed, as the separators are allowed only between values and must not preced the group closing bracket the nesting depth is hardcoded to 16, counting the global group The API provides functions to print simple values and some helpers to format more complex structures. Signed-off-by: David Sterba --- Makefile | 2 +- common/format-output.c | 314 +++++++++++++++++++++++++++++++++++++++++ common/format-output.h | 90 ++++++++++++ 3 files changed, 405 insertions(+), 1 deletion(-) create mode 100644 common/format-output.c create mode 100644 common/format-output.h diff --git a/Makefile b/Makefile index 8ae28c4d..2ffe89f2 100644 --- a/Makefile +++ b/Makefile @@ -134,7 +134,7 @@ objects = ctree.o disk-io.o kernel-lib/radix-tree.o extent-tree.o print-tree.o \ common/task-utils.o \ inode.o file.o find-root.o free-space-tree.o common/help.o send-dump.o \ common/fsfeatures.o kernel-lib/tables.o kernel-lib/raid56.o transaction.o \ - delayed-ref.o + delayed-ref.o common/format-output.o cmds_objects = cmds/subvolume.o cmds/filesystem.o cmds/device.o cmds/scrub.o \ cmds/inspect.o cmds/balance.o cmds/send.o cmds/receive.o \ cmds/quota.o cmds/qgroup.o cmds/replace.o check/main.o \ diff --git a/common/format-output.c b/common/format-output.c new file mode 100644 index 00000000..c5f1b51f --- /dev/null +++ b/common/format-output.c @@ -0,0 +1,314 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include "kerncompat.h" +#include +#include +#include "common-defs.h" +#include "common/format-output.h" +#include "common/utils.h" +#include "cmds/commands.h" + +static void print_uuid(const u8 *uuid) +{ + char uuidparse[BTRFS_UUID_UNPARSED_SIZE]; + + if (uuid_is_null(uuid)) { + putchar('-'); + } else { + uuid_unparse(uuid, uuidparse); + printf("%s", uuidparse); + } +} + +static void fmt_indent1(int indent) +{ + while (indent--) + putchar(' '); +} + +static void fmt_indent2(int indent) +{ + while (indent--) { + putchar(' '); + putchar(' '); + } +} + +static void fmt_error(struct format_ctx *fctx) +{ + printf("INTERNAL ERROR: formatting json: depth=%d\n", fctx->depth); + exit(1); +} + +static void fmt_inc_depth(struct format_ctx *fctx) +{ + if (fctx->depth >= JSON_NESTING_LIMIT - 1) { + printf("INTERNAL ERROR: nesting too deep, limit %d\n", + JSON_NESTING_LIMIT); + exit(1); + } + fctx->depth++; +} + +static void fmt_dec_depth(struct format_ctx *fctx) +{ + if (fctx->depth < 1) { + printf("INTERNAL ERROR: nesting below first level\n"); + exit(1); + } + fctx->depth--; +} + +static void fmt_separator(struct format_ctx *fctx) +{ + if (bconf.output_format == CMD_FORMAT_JSON) { + /* Check current depth */ + if (fctx->memb[fctx->depth] == 0) { + /* First member, only indent */ + putchar('\n'); + fmt_indent2(fctx->depth); + fctx->memb[fctx->depth] = 1; + } else if (fctx->memb[fctx->depth] == 1) { + /* Something has been printed already */ + printf(",\n"); + fmt_indent2(fctx->depth); + fctx->memb[fctx->depth] = 2; + } else { + /* N-th member */ + printf(",\n"); + fmt_indent2(fctx->depth); + } + } +} + +void fmt_start(struct format_ctx *fctx, const struct rowspec *spec, int width, + int indent) +{ + fctx->width = width; + fctx->indent = indent; + fctx->rowspec = spec; + fctx->depth = 1; + + if (bconf.output_format & CMD_FORMAT_JSON) { + putchar('{'); + /* The top level is a map and is the first one */ + fctx->jtype[fctx->depth] = JSON_TYPE_MAP; + fctx->memb[fctx->depth] = 0; + fmt_print_start_group(fctx, "__header", JSON_TYPE_MAP); + fmt_separator(fctx); + printf("\"version\": \"1\""); + fctx->memb[fctx->depth] = 1; + fmt_print_end_group(fctx, "__header"); + } +} + +void fmt_end(struct format_ctx *fctx) +{ + if (fctx->depth != 1) + fprintf(stderr, "WARNING: wrong nesting\n"); + + /* Close, no continuation to print */ + + if (bconf.output_format & CMD_FORMAT_TEXT) + putchar('\n'); + else if (bconf.output_format & CMD_FORMAT_JSON) { + fmt_dec_depth(fctx); + fmt_separator(fctx); + printf("}\n"); + } +} + +void fmt_start_list_value(struct format_ctx *fctx) +{ + if (bconf.output_format == CMD_FORMAT_TEXT) { + fmt_indent1(fctx->indent); + } else if (bconf.output_format == CMD_FORMAT_JSON) { + fmt_separator(fctx); + fmt_indent2(fctx->depth); + putchar('"'); + } +} + +void fmt_end_list_value(struct format_ctx *fctx) +{ + if (bconf.output_format == CMD_FORMAT_TEXT) + putchar('\n'); + else if (bconf.output_format == CMD_FORMAT_JSON) + putchar('"'); +} + +void fmt_start_value(struct format_ctx *fctx, const struct rowspec *row) +{ + if (bconf.output_format == CMD_FORMAT_TEXT) { + if (strcmp(row->fmt, "list") == 0) + putchar('\n'); + else if (strcmp(row->fmt, "map") == 0) + putchar('\n'); + } else if (bconf.output_format == CMD_FORMAT_JSON) { + if (strcmp(row->fmt, "list") == 0) { + } else if (strcmp(row->fmt, "map") == 0) { + } else { + putchar('"'); + } + } +} + +void fmt_end_value(struct format_ctx *fctx, const struct rowspec *row) +{ + if (bconf.output_format == CMD_FORMAT_JSON) { + if (strcmp(row->fmt, "list") == 0) { + } else if (strcmp(row->fmt, "map") == 0) { + } else { + putchar('"'); + } + } +} + +void fmt_print_start_group(struct format_ctx *fctx, const char *name, + enum json_type jtype) +{ + if (bconf.output_format == CMD_FORMAT_JSON) { + fmt_separator(fctx); + fmt_inc_depth(fctx); + fctx->jtype[fctx->depth] = jtype; + fctx->memb[fctx->depth] = 0; + if (jtype == JSON_TYPE_MAP) + printf("\"%s\": {", name); + else if (jtype == JSON_TYPE_ARRAY) + printf("\"%s\": [", name); + else + fmt_error(fctx); + } +} + +void fmt_print_end_group(struct format_ctx *fctx, const char *name) +{ + if (bconf.output_format == CMD_FORMAT_JSON) { + /* Whatever was on previous line won't continue with "," */ + const enum json_type jtype = fctx->jtype[fctx->depth]; + + fmt_dec_depth(fctx); + putchar('\n'); + fmt_indent2(fctx->depth); + if (jtype == JSON_TYPE_MAP) + putchar('}'); + else if (jtype == JSON_TYPE_ARRAY) + putchar(']'); + else + fmt_error(fctx); + } +} + +/* Use rowspec to print according to currently set output format */ +void fmt_print(struct format_ctx *fctx, const char* key, ...) +{ + va_list args; + const struct rowspec *row; + bool found = false; + + va_start(args, key); + row = &fctx->rowspec[0]; + + while (row->key) { + if (strcmp(key, row->key) == 0) { + found = true; + break; + } + row++; + } + if (!found) { + printf("INTERNAL ERROR: unknown key: %s\n", key); + exit(1); + } + + if (bconf.output_format == CMD_FORMAT_TEXT) { + const bool print_colon = row->out_text[0]; + int len; + + putchar('\n'); + fmt_indent1(fctx->indent); + len = strlen(row->out_text); + + printf("%s", row->out_text); + if (print_colon) { + putchar(':'); + len++; + } + fmt_indent1(fctx->width - len); + } else if (bconf.output_format == CMD_FORMAT_JSON) { + if (strcmp(row->fmt, "list") == 0) { + fmt_print_start_group(fctx, row->out_json, + JSON_TYPE_ARRAY); + } else if (strcmp(row->fmt, "map") == 0) { + fmt_print_start_group(fctx, row->out_json, + JSON_TYPE_MAP); + } else { + /* Simple key/values */ + fmt_separator(fctx); + printf("\"%s\": ", row->out_json); + } + } + + fmt_start_value(fctx, row); + + if (row->fmt[0] == '%') { + vprintf(row->fmt, args); + } else if (strcmp(row->fmt, "uuid") == 0) { + const u8 *uuid = va_arg(args, const u8*); + + print_uuid(uuid); + } else if (strcmp(row->fmt, "time-long") == 0) { + const time_t ts = va_arg(args, time_t); + + if (ts) { + char tstr[256]; + struct tm tm; + + localtime_r(&ts, &tm); + strftime(tstr, 256, "%Y-%m-%d %X %z", &tm); + printf(tstr); + } else { + putchar('-'); + } + } else if (strcmp(row->fmt, "list") == 0) { + } else if (strcmp(row->fmt, "map") == 0) { + } else if (strcmp(row->fmt, "qgroupid") == 0) { + const u64 level = va_arg(args, u64); + const u64 id = va_arg(args, u64); + + printf("%llu/%llu", level, id); + } else if (strcmp(row->fmt, "size-or-none") == 0) { + const u64 size = va_arg(args, u64); + const unsigned int unit_mode = va_arg(args, unsigned int); + + if (size) + printf("%s", pretty_size_mode(size, unit_mode)); + else + putchar('-'); + } else if (strcmp(row->fmt, "size") == 0) { + const u64 size = va_arg(args, u64); + const unsigned int unit_mode = va_arg(args, unsigned int); + + printf("%s", pretty_size_mode(size, unit_mode)); + } else { + printf("INTERNAL ERROR: unknown format %s\n", row->fmt); + } + + fmt_end_value(fctx, row); + /* No newline here, the line is closed by next value or group end */ + va_end(args); +} diff --git a/common/format-output.h b/common/format-output.h new file mode 100644 index 00000000..b73f53ba --- /dev/null +++ b/common/format-output.h @@ -0,0 +1,90 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#ifndef __BTRFS_FORMAT_OUTPUT_H__ +#define __BTRFS_FORMAT_OUTPUT_H__ + +struct rowspec { + /* Identifier for the row */ + const char *key; + /* + * Format to print: + * - starting with %: must be a valid printf spec + * (values: va_args) + * - uuid: format UUID as text + * (value: u8 *uuid) + * - list: print list opening bracket [ + * (values printed separately) + * - map: start a new group, opens { + * (values printed separately) + * - size: pretty print size according to + * (values: u64 size, u32 unit_type) + * - size-or-none: pretty print non-zero values, "-" otherwise + * (values: same as "size") + * - qgroupid: print qgroup from separate level and id + * (values: u64 level, u64 id) + */ + const char *fmt; + /* String to print in format:text */ + const char *out_text; + /* String to print in format:json, is quoted */ + const char *out_json; +}; + +#define ROWSPEC_END { .key = NULL }, +#define JSON_NESTING_LIMIT 16 + +/* + * Nested types + */ +enum json_type { + JSON_TYPE_INVALID, + JSON_TYPE_MAP, + JSON_TYPE_ARRAY, +}; + +struct format_ctx { + /* Preferred width of the first column with key (format: text) */ + int width; + /* Initial indentation before the first column (format: text) */ + int indent; + /* Nesting of groups like lists or maps (format: json) */ + int depth; + + /* Array of named output fileds as defined by the command */ + const struct rowspec *rowspec; + + char jtype[JSON_NESTING_LIMIT]; + enum json_type memb[JSON_NESTING_LIMIT]; +}; + +void fmt_start(struct format_ctx *fctx, const struct rowspec *spec, int width, + int indent); +void fmt_end(struct format_ctx *fctx); + +void fmt_print(struct format_ctx *fctx, const char* key, ...); + +void fmt_start_list_value(struct format_ctx *fctx); +void fmt_end_list_value(struct format_ctx *fctx); + +void fmt_start_value(struct format_ctx *fctx, const struct rowspec *row); +void fmt_end_value(struct format_ctx *fctx, const struct rowspec *row); + +void fmt_print_start_group(struct format_ctx *fctx, const char *name, + enum json_type jtype); +void fmt_print_end_group(struct format_ctx *fctx, const char *name); + +#endif