kern/{fmt,shell}: update from upstream

The shell module has been "objectified" and now supports multiple
instances with shareable command sets.

1 files changed, 139 insertions, 0 deletions

diff --git a/kern/shell_i.h b/kern/shell_i.h
new file mode 100644
index 00000000..df1f4fa5
--- /dev/null
+++ b/kern/shell_i.h
@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2018 Richard Braun.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ *
+ * Upstream site with license notes :
+ * http://git.sceen.net/rbraun/librbraun.git/
+ */
+
+#ifndef KERN_SHELL_I_H
+#define KERN_SHELL_I_H
+
+#include <stddef.h>
+
+#include <kern/macros.h>
+#include <kern/mutex.h>
+
+struct shell_cmd {
+    struct shell_cmd *ht_next;
+    struct shell_cmd *ls_next;
+    const char *name;
+    shell_fn_t fn;
+    const char *usage;
+    const char *short_desc;
+    const char *long_desc;
+};
+
+struct shell_bucket {
+    struct shell_cmd *cmd;
+};
+
+/*
+ * Binary exponent and size of the hash table used to store commands.
+ */
+#define SHELL_HTABLE_BITS   6
+#define SHELL_HTABLE_SIZE   (1 << SHELL_HTABLE_BITS)
+
+/*
+ * The command list is sorted.
+ */
+struct shell_cmd_set {
+    struct mutex lock;
+    struct shell_bucket htable[SHELL_HTABLE_SIZE];
+    struct shell_cmd *cmd_list;
+};
+
+#define SHELL_LINE_MAX_SIZE 64
+
+/*
+ * Line containing a shell entry.
+ *
+ * The string must be nul-terminated. The size doesn't include this
+ * additional nul character, the same way strlen() doesn't account for it.
+ */
+struct shell_line {
+    char str[SHELL_LINE_MAX_SIZE];
+    size_t size;
+};
+
+/*
+ * Number of entries in the history.
+ *
+ * One of these entryes is used as the current line.
+ */
+#define SHELL_HISTORY_SIZE 21
+
+#if SHELL_HISTORY_SIZE == 0
+#error "shell history size must be non-zero"
+#endif /* SHELL_HISTORY_SIZE == 0 */
+
+/*
+ * Shell history.
+ *
+ * The history is never empty. There is always at least one entry, the
+ * current line, referenced by the newest (most recent) index. The array
+ * is used like a circular buffer, i.e. old entries are implicitely
+ * erased by new ones. The index references the entry used as a template
+ * for the current line.
+ */
+struct shell_history {
+    struct shell_line lines[SHELL_HISTORY_SIZE];
+    size_t newest;
+    size_t oldest;
+    size_t index;
+};
+
+/*
+ * This value changes depending on the standard used and was chosen arbitrarily.
+ */
+#define SHELL_ESC_SEQ_MAX_SIZE 8
+
+#define SHELL_MAX_ARGS 16
+
+/*
+ * Shell structure.
+ *
+ * A shell instance can include temporary variables to minimize stack usage.
+ */
+struct shell {
+    struct shell_cmd_set *cmd_set;
+
+    shell_getc_fn_t getc_fn;
+    shell_vfprintf_fn_t vfprintf_fn;
+    void *io_object;
+
+    struct shell_history history;
+
+    /* Cursor within the current line */
+    size_t cursor;
+
+    /* Members used for escape sequence parsing */
+    char esc_seq[SHELL_ESC_SEQ_MAX_SIZE];
+    size_t esc_seq_index;
+
+    /*
+     * Buffer used to store the current line during argument processing.
+     *
+     * The pointers in the argv array point inside this buffer. The
+     * separators immediately following the arguments are replaced with
+     * null characters.
+     */
+    char tmp_line[SHELL_LINE_MAX_SIZE];
+
+    int argc;
+    char *argv[SHELL_MAX_ARGS];
+};
+
+#endif /* KERN_SHELL_I_H */