diff options
Diffstat (limited to 'plugins/packagekit/gs-markdown.c')
| -rw-r--r-- | plugins/packagekit/gs-markdown.c | 856 |
1 files changed, 856 insertions, 0 deletions
diff --git a/plugins/packagekit/gs-markdown.c b/plugins/packagekit/gs-markdown.c new file mode 100644 index 0000000..b7be06b --- /dev/null +++ b/plugins/packagekit/gs-markdown.c @@ -0,0 +1,856 @@ +/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- + * vi:set noexpandtab tabstop=8 shiftwidth=8: + * + * Copyright (C) 2008 Richard Hughes <richard@hughsie.com> + * Copyright (C) 2015 Kalev Lember <klember@redhat.com> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include "config.h" + +#include <string.h> +#include <glib.h> + +#include "gs-markdown.h" + +/******************************************************************************* + * + * This is a simple Markdown parser. + * It can output to Pango, HTML or plain text. The following limitations are + * already known, and properly deliberate: + * + * - No code section support + * - No ordered list support + * - No blockquote section support + * - No image support + * - No links or email support + * - No backslash escapes support + * - No HTML escaping support + * - Auto-escapes certain word patterns, like http:// + * + * It does support the rest of the standard pretty well, although it's not + * been run against any conformance tests. The parsing is single pass, with + * a simple enumerated interpretor mode and a single line back-memory. + * + ******************************************************************************/ + +typedef enum { + GS_MARKDOWN_MODE_BLANK, + GS_MARKDOWN_MODE_RULE, + GS_MARKDOWN_MODE_BULLETT, + GS_MARKDOWN_MODE_PARA, + GS_MARKDOWN_MODE_H1, + GS_MARKDOWN_MODE_H2, + GS_MARKDOWN_MODE_UNKNOWN +} GsMarkdownMode; + +typedef struct { + const gchar *em_start; + const gchar *em_end; + const gchar *strong_start; + const gchar *strong_end; + const gchar *code_start; + const gchar *code_end; + const gchar *h1_start; + const gchar *h1_end; + const gchar *h2_start; + const gchar *h2_end; + const gchar *bullet_start; + const gchar *bullet_end; + const gchar *rule; +} GsMarkdownTags; + +struct _GsMarkdown { + GObject parent_instance; + + GsMarkdownMode mode; + GsMarkdownTags tags; + GsMarkdownOutputKind output; + gint max_lines; + gint line_count; + gboolean smart_quoting; + gboolean escape; + gboolean autocode; + gboolean autolinkify; + GString *pending; + GString *processed; +}; + +G_DEFINE_TYPE (GsMarkdown, gs_markdown, G_TYPE_OBJECT) + +/* + * gs_markdown_to_text_line_is_rule: + * + * Horizontal rules are created by placing three or more hyphens, asterisks, + * or underscores on a line by themselves. + * You may use spaces between the hyphens or asterisks. + **/ +static gboolean +gs_markdown_to_text_line_is_rule (const gchar *line) +{ + guint i; + guint len; + guint count = 0; + g_autofree gchar *copy = NULL; + + len = (guint) strlen (line); + if (len == 0) + return FALSE; + + /* replace non-rule chars with ~ */ + copy = g_strdup (line); + g_strcanon (copy, "-*_ ", '~'); + for (i = 0; i < len; i++) { + if (copy[i] == '~') + return FALSE; + if (copy[i] != ' ') + count++; + } + + /* if we matched, return true */ + if (count >= 3) + return TRUE; + return FALSE; +} + +static gboolean +gs_markdown_to_text_line_is_bullet (const gchar *line) +{ + return (g_str_has_prefix (line, "- ") || + g_str_has_prefix (line, "* ") || + g_str_has_prefix (line, "+ ") || + g_str_has_prefix (line, " - ") || + g_str_has_prefix (line, " * ") || + g_str_has_prefix (line, " + ")); +} + +static gboolean +gs_markdown_to_text_line_is_header1 (const gchar *line) +{ + return g_str_has_prefix (line, "# "); +} + +static gboolean +gs_markdown_to_text_line_is_header2 (const gchar *line) +{ + return g_str_has_prefix (line, "## "); +} + +static gboolean +gs_markdown_to_text_line_is_header1_type2 (const gchar *line) +{ + return g_str_has_prefix (line, "==="); +} + +static gboolean +gs_markdown_to_text_line_is_header2_type2 (const gchar *line) +{ + return g_str_has_prefix (line, "---"); +} + +#if 0 +static gboolean +gs_markdown_to_text_line_is_code (const gchar *line) +{ + return (g_str_has_prefix (line, " ") || + g_str_has_prefix (line, "\t")); +} + +static gboolean +gs_markdown_to_text_line_is_blockquote (const gchar *line) +{ + return (g_str_has_prefix (line, "> ")); +} +#endif + +static gboolean +gs_markdown_to_text_line_is_blank (const gchar *line) +{ + guint i; + guint len; + + /* a line with no characters is blank by definition */ + len = (guint) strlen (line); + if (len == 0) + return TRUE; + + /* find if there are only space chars */ + for (i = 0; i < len; i++) { + if (line[i] != ' ' && line[i] != '\t') + return FALSE; + } + + /* if we matched, return true */ + return TRUE; +} + +static gchar * +gs_markdown_replace (const gchar *haystack, + const gchar *needle, + const gchar *replace) +{ + g_auto(GStrv) split = NULL; + split = g_strsplit (haystack, needle, -1); + return g_strjoinv (replace, split); +} + +static gchar * +gs_markdown_strstr_spaces (const gchar *haystack, const gchar *needle) +{ + gchar *found; + const gchar *haystack_new = haystack; + +retry: + /* don't find if surrounded by spaces */ + found = strstr (haystack_new, needle); + if (found == NULL) + return NULL; + + /* start of the string, always valid */ + if (found == haystack) + return found; + + /* end of the string, always valid */ + if (*(found-1) == ' ' && *(found+1) == ' ') { + haystack_new = found+1; + goto retry; + } + return found; +} + +static gchar * +gs_markdown_to_text_line_formatter (const gchar *line, + const gchar *formatter, + const gchar *left, + const gchar *right) +{ + guint len; + gchar *str1; + gchar *str2; + gchar *start = NULL; + gchar *middle = NULL; + gchar *end = NULL; + g_autofree gchar *copy = NULL; + + /* needed to know for shifts */ + len = (guint) strlen (formatter); + if (len == 0) + return NULL; + + /* find sections */ + copy = g_strdup (line); + str1 = gs_markdown_strstr_spaces (copy, formatter); + if (str1 != NULL) { + *str1 = '\0'; + str2 = gs_markdown_strstr_spaces (str1+len, formatter); + if (str2 != NULL) { + *str2 = '\0'; + middle = str1 + len; + start = copy; + end = str2 + len; + } + } + + /* if we found, replace and keep looking for the same string */ + if (start != NULL && middle != NULL && end != NULL) { + g_autofree gchar *temp = NULL; + temp = g_strdup_printf ("%s%s%s%s%s", start, left, middle, right, end); + /* recursive */ + return gs_markdown_to_text_line_formatter (temp, formatter, left, right); + } + + /* not found, keep return as-is */ + return g_strdup (line); +} + +static gchar * +gs_markdown_to_text_line_format_sections (GsMarkdown *self, const gchar *line) +{ + gchar *data = g_strdup (line); + gchar *temp; + + /* bold1 */ + temp = data; + data = gs_markdown_to_text_line_formatter (temp, "**", + self->tags.strong_start, + self->tags.strong_end); + g_free (temp); + + /* bold2 */ + temp = data; + data = gs_markdown_to_text_line_formatter (temp, "__", + self->tags.strong_start, + self->tags.strong_end); + g_free (temp); + + /* italic1 */ + temp = data; + data = gs_markdown_to_text_line_formatter (temp, "*", + self->tags.em_start, + self->tags.em_end); + g_free (temp); + + /* italic2 */ + temp = data; + data = gs_markdown_to_text_line_formatter (temp, "_", + self->tags.em_start, + self->tags.em_end); + g_free (temp); + + /* em-dash */ + temp = data; + data = gs_markdown_replace (temp, " -- ", " — "); + g_free (temp); + + /* smart quoting */ + if (self->smart_quoting) { + temp = data; + data = gs_markdown_to_text_line_formatter (temp, "\"", "“", "”"); + g_free (temp); + + temp = data; + data = gs_markdown_to_text_line_formatter (temp, "'", "‘", "’"); + g_free (temp); + } + + return data; +} + +static gchar * +gs_markdown_to_text_line_format (GsMarkdown *self, const gchar *line) +{ + GString *string; + gboolean mode = FALSE; + gchar *text; + guint i; + g_auto(GStrv) codes = NULL; + + /* optimise the trivial case where we don't have any code tags */ + text = strstr (line, "`"); + if (text == NULL) + return gs_markdown_to_text_line_format_sections (self, line); + + /* we want to parse the code sections without formatting */ + codes = g_strsplit (line, "`", -1); + string = g_string_new (""); + for (i = 0; codes[i] != NULL; i++) { + if (!mode) { + text = gs_markdown_to_text_line_format_sections (self, codes[i]); + g_string_append (string, text); + g_free (text); + mode = TRUE; + } else { + /* just append without formatting */ + g_string_append (string, self->tags.code_start); + g_string_append (string, codes[i]); + g_string_append (string, self->tags.code_end); + mode = FALSE; + } + } + return g_string_free (string, FALSE); +} + +static gboolean +gs_markdown_add_pending (GsMarkdown *self, const gchar *line) +{ + g_autofree gchar *copy = NULL; + + /* would put us over the limit */ + if (self->max_lines > 0 && self->line_count >= self->max_lines) + return FALSE; + + copy = g_strdup (line); + + /* strip leading and trailing spaces */ + g_strstrip (copy); + + /* append */ + g_string_append_printf (self->pending, "%s ", copy); + return TRUE; +} + +static gboolean +gs_markdown_add_pending_header (GsMarkdown *self, const gchar *line) +{ + g_autofree gchar *copy = NULL; + + /* strip trailing # */ + copy = g_strdup (line); + g_strdelimit (copy, "#", ' '); + return gs_markdown_add_pending (self, copy); +} + +static guint +gs_markdown_count_chars_in_word (const gchar *text, gchar find) +{ + guint i; + guint len; + guint count = 0; + + /* get length */ + len = (guint) strlen (text); + if (len == 0) + return 0; + + /* find matching chars */ + for (i = 0; i < len; i++) { + if (text[i] == find) + count++; + } + return count; +} + +static gboolean +gs_markdown_word_is_code (const gchar *text) +{ + /* already code */ + if (g_str_has_prefix (text, "`")) + return FALSE; + if (g_str_has_suffix (text, "`")) + return FALSE; + + /* paths */ + if (g_str_has_prefix (text, "/")) + return TRUE; + + /* bugzillas */ + if (g_str_has_prefix (text, "#")) + return TRUE; + + /* patch files */ + if (g_strrstr (text, ".patch") != NULL) + return TRUE; + if (g_strrstr (text, ".diff") != NULL) + return TRUE; + + /* function names */ + if (g_strrstr (text, "()") != NULL) + return TRUE; + + /* email addresses */ + if (g_strrstr (text, "@") != NULL) + return TRUE; + + /* compiler defines */ + if (text[0] != '_' && + gs_markdown_count_chars_in_word (text, '_') > 1) + return TRUE; + + /* nothing special */ + return FALSE; +} + +static gchar * +gs_markdown_word_auto_format_code (const gchar *text) +{ + guint i; + gchar *temp; + gboolean ret = FALSE; + g_auto(GStrv) words = NULL; + + /* split sentence up with space */ + words = g_strsplit (text, " ", -1); + + /* search each word */ + for (i = 0; words[i] != NULL; i++) { + if (gs_markdown_word_is_code (words[i])) { + temp = g_strdup_printf ("`%s`", words[i]); + g_free (words[i]); + words[i] = temp; + ret = TRUE; + } + } + + /* no replacements, so just return a copy */ + if (!ret) + return g_strdup (text); + + /* join the array back into a string */ + return g_strjoinv (" ", words); +} + +static gboolean +gs_markdown_word_is_url (const gchar *text) +{ + if (g_str_has_prefix (text, "http://")) + return TRUE; + if (g_str_has_prefix (text, "https://")) + return TRUE; + if (g_str_has_prefix (text, "ftp://")) + return TRUE; + return FALSE; +} + +static gchar * +gs_markdown_word_auto_format_urls (const gchar *text) +{ + guint i; + gchar *temp; + gboolean ret = FALSE; + g_auto(GStrv) words = NULL; + + /* split sentence up with space */ + words = g_strsplit (text, " ", -1); + + /* search each word */ + for (i = 0; words[i] != NULL; i++) { + if (gs_markdown_word_is_url (words[i])) { + temp = g_strdup_printf ("<a href=\"%s\">%s</a>", + words[i], words[i]); + g_free (words[i]); + words[i] = temp; + ret = TRUE; + } + } + + /* no replacements, so just return a copy */ + if (!ret) + return g_strdup (text); + + /* join the array back into a string */ + return g_strjoinv (" ", words); +} + +static void +gs_markdown_flush_pending (GsMarkdown *self) +{ + g_autofree gchar *copy = NULL; + g_autofree gchar *temp = NULL; + + /* no data yet */ + if (self->mode == GS_MARKDOWN_MODE_UNKNOWN) + return; + + /* remove trailing spaces */ + while (g_str_has_suffix (self->pending->str, " ")) + g_string_set_size (self->pending, self->pending->len - 1); + + /* pango requires escaping */ + copy = g_strdup (self->pending->str); + if (!self->escape && self->output == GS_MARKDOWN_OUTPUT_PANGO) { + g_strdelimit (copy, "<", '('); + g_strdelimit (copy, ">", ')'); + g_strdelimit (copy, "&", '+'); + } + + /* check words for code */ + if (self->autocode && + (self->mode == GS_MARKDOWN_MODE_PARA || + self->mode == GS_MARKDOWN_MODE_BULLETT)) { + temp = gs_markdown_word_auto_format_code (copy); + g_free (copy); + copy = temp; + } + + /* escape */ + if (self->escape) { + temp = g_markup_escape_text (copy, -1); + g_free (copy); + copy = temp; + } + + /* check words for URLS */ + if (self->autolinkify && + self->output == GS_MARKDOWN_OUTPUT_PANGO && + (self->mode == GS_MARKDOWN_MODE_PARA || + self->mode == GS_MARKDOWN_MODE_BULLETT)) { + temp = gs_markdown_word_auto_format_urls (copy); + g_free (copy); + copy = temp; + } + + /* do formatting */ + temp = gs_markdown_to_text_line_format (self, copy); + if (self->mode == GS_MARKDOWN_MODE_BULLETT) { + g_string_append_printf (self->processed, "%s%s%s\n", + self->tags.bullet_start, + temp, + self->tags.bullet_end); + self->line_count++; + } else if (self->mode == GS_MARKDOWN_MODE_H1) { + g_string_append_printf (self->processed, "%s%s%s\n", + self->tags.h1_start, + temp, + self->tags.h1_end); + } else if (self->mode == GS_MARKDOWN_MODE_H2) { + g_string_append_printf (self->processed, "%s%s%s\n", + self->tags.h2_start, + temp, + self->tags.h2_end); + } else if (self->mode == GS_MARKDOWN_MODE_PARA || + self->mode == GS_MARKDOWN_MODE_RULE) { + g_string_append_printf (self->processed, "%s\n", temp); + self->line_count++; + } + + /* clear */ + g_string_truncate (self->pending, 0); +} + +static gboolean +gs_markdown_to_text_line_process (GsMarkdown *self, const gchar *line) +{ + gboolean ret; + + /* blank */ + ret = gs_markdown_to_text_line_is_blank (line); + if (ret) { + gs_markdown_flush_pending (self); + /* a new line after a list is the end of list, not a gap */ + if (self->mode != GS_MARKDOWN_MODE_BULLETT) + ret = gs_markdown_add_pending (self, "\n"); + self->mode = GS_MARKDOWN_MODE_BLANK; + goto out; + } + + /* header1_type2 */ + ret = gs_markdown_to_text_line_is_header1_type2 (line); + if (ret) { + if (self->mode == GS_MARKDOWN_MODE_PARA) + self->mode = GS_MARKDOWN_MODE_H1; + goto out; + } + + /* header2_type2 */ + ret = gs_markdown_to_text_line_is_header2_type2 (line); + if (ret) { + if (self->mode == GS_MARKDOWN_MODE_PARA) + self->mode = GS_MARKDOWN_MODE_H2; + goto out; + } + + /* rule */ + ret = gs_markdown_to_text_line_is_rule (line); + if (ret) { + gs_markdown_flush_pending (self); + self->mode = GS_MARKDOWN_MODE_RULE; + ret = gs_markdown_add_pending (self, self->tags.rule); + goto out; + } + + /* bullet */ + ret = gs_markdown_to_text_line_is_bullet (line); + if (ret) { + gs_markdown_flush_pending (self); + self->mode = GS_MARKDOWN_MODE_BULLETT; + ret = gs_markdown_add_pending (self, &line[2]); + goto out; + } + + /* header1 */ + ret = gs_markdown_to_text_line_is_header1 (line); + if (ret) { + gs_markdown_flush_pending (self); + self->mode = GS_MARKDOWN_MODE_H1; + ret = gs_markdown_add_pending_header (self, &line[2]); + goto out; + } + + /* header2 */ + ret = gs_markdown_to_text_line_is_header2 (line); + if (ret) { + gs_markdown_flush_pending (self); + self->mode = GS_MARKDOWN_MODE_H2; + ret = gs_markdown_add_pending_header (self, &line[3]); + goto out; + } + + /* paragraph */ + if (self->mode == GS_MARKDOWN_MODE_BLANK || + self->mode == GS_MARKDOWN_MODE_UNKNOWN) { + gs_markdown_flush_pending (self); + self->mode = GS_MARKDOWN_MODE_PARA; + } + + /* add to pending */ + ret = gs_markdown_add_pending (self, line); +out: + /* if we failed to add, we don't know the mode */ + if (!ret) + self->mode = GS_MARKDOWN_MODE_UNKNOWN; + return ret; +} + +static void +gs_markdown_set_output_kind (GsMarkdown *self, GsMarkdownOutputKind output) +{ + g_return_if_fail (GS_IS_MARKDOWN (self)); + + self->output = output; + switch (output) { + case GS_MARKDOWN_OUTPUT_PANGO: + /* PangoMarkup */ + self->tags.em_start = "<i>"; + self->tags.em_end = "</i>"; + self->tags.strong_start = "<b>"; + self->tags.strong_end = "</b>"; + self->tags.code_start = "<tt>"; + self->tags.code_end = "</tt>"; + self->tags.h1_start = "<big>"; + self->tags.h1_end = "</big>"; + self->tags.h2_start = "<b>"; + self->tags.h2_end = "</b>"; + self->tags.bullet_start = "• "; + self->tags.bullet_end = ""; + self->tags.rule = "⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯\n"; + self->escape = TRUE; + self->autolinkify = TRUE; + break; + case GS_MARKDOWN_OUTPUT_HTML: + /* XHTML */ + self->tags.em_start = "<em>"; + self->tags.em_end = "<em>"; + self->tags.strong_start = "<strong>"; + self->tags.strong_end = "</strong>"; + self->tags.code_start = "<code>"; + self->tags.code_end = "</code>"; + self->tags.h1_start = "<h1>"; + self->tags.h1_end = "</h1>"; + self->tags.h2_start = "<h2>"; + self->tags.h2_end = "</h2>"; + self->tags.bullet_start = "<li>"; + self->tags.bullet_end = "</li>"; + self->tags.rule = "<hr>"; + self->escape = TRUE; + self->autolinkify = TRUE; + break; + case GS_MARKDOWN_OUTPUT_TEXT: + /* plain text */ + self->tags.em_start = ""; + self->tags.em_end = ""; + self->tags.strong_start = ""; + self->tags.strong_end = ""; + self->tags.code_start = ""; + self->tags.code_end = ""; + self->tags.h1_start = "["; + self->tags.h1_end = "]"; + self->tags.h2_start = "-"; + self->tags.h2_end = "-"; + self->tags.bullet_start = "* "; + self->tags.bullet_end = ""; + self->tags.rule = " ----- \n"; + self->escape = FALSE; + self->autolinkify = FALSE; + break; + default: + g_warning ("unknown output enum"); + break; + } +} + +void +gs_markdown_set_max_lines (GsMarkdown *self, gint max_lines) +{ + g_return_if_fail (GS_IS_MARKDOWN (self)); + self->max_lines = max_lines; +} + +void +gs_markdown_set_smart_quoting (GsMarkdown *self, gboolean smart_quoting) +{ + g_return_if_fail (GS_IS_MARKDOWN (self)); + self->smart_quoting = smart_quoting; +} + +void +gs_markdown_set_escape (GsMarkdown *self, gboolean escape) +{ + g_return_if_fail (GS_IS_MARKDOWN (self)); + self->escape = escape; +} + +void +gs_markdown_set_autocode (GsMarkdown *self, gboolean autocode) +{ + g_return_if_fail (GS_IS_MARKDOWN (self)); + self->autocode = autocode; +} + +void +gs_markdown_set_autolinkify (GsMarkdown *self, gboolean autolinkify) +{ + g_return_if_fail (GS_IS_MARKDOWN (self)); + self->autolinkify = autolinkify; +} + +gchar * +gs_markdown_parse (GsMarkdown *self, const gchar *markdown) +{ + gboolean ret; + gchar *temp; + guint i; + guint len; + g_auto(GStrv) lines = NULL; + + g_return_val_if_fail (GS_IS_MARKDOWN (self), NULL); + + /* process */ + self->mode = GS_MARKDOWN_MODE_UNKNOWN; + self->line_count = 0; + g_string_truncate (self->pending, 0); + g_string_truncate (self->processed, 0); + lines = g_strsplit (markdown, "\n", -1); + len = g_strv_length (lines); + + /* process each line */ + for (i = 0; i < len; i++) { + ret = gs_markdown_to_text_line_process (self, lines[i]); + if (!ret) + break; + } + gs_markdown_flush_pending (self); + + /* remove trailing \n */ + while (g_str_has_suffix (self->processed->str, "\n")) + g_string_set_size (self->processed, self->processed->len - 1); + + /* get a copy */ + temp = g_strdup (self->processed->str); + g_string_truncate (self->pending, 0); + g_string_truncate (self->processed, 0); + return temp; +} + +static void +gs_markdown_finalize (GObject *object) +{ + GsMarkdown *self; + + g_return_if_fail (GS_IS_MARKDOWN (object)); + + self = GS_MARKDOWN (object); + + g_string_free (self->pending, TRUE); + g_string_free (self->processed, TRUE); + + G_OBJECT_CLASS (gs_markdown_parent_class)->finalize (object); +} + +static void +gs_markdown_class_init (GsMarkdownClass *klass) +{ + GObjectClass *object_class = G_OBJECT_CLASS (klass); + object_class->finalize = gs_markdown_finalize; +} + +static void +gs_markdown_init (GsMarkdown *self) +{ + self->mode = GS_MARKDOWN_MODE_UNKNOWN; + self->pending = g_string_new (""); + self->processed = g_string_new (""); + self->max_lines = -1; + self->smart_quoting = FALSE; + self->escape = FALSE; + self->autocode = FALSE; +} + +GsMarkdown * +gs_markdown_new (GsMarkdownOutputKind output) +{ + GsMarkdown *self; + self = g_object_new (GS_TYPE_MARKDOWN, NULL); + gs_markdown_set_output_kind (self, output); + return GS_MARKDOWN (self); +} |