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-rw-r--r--utils.c711
1 files changed, 0 insertions, 711 deletions
diff --git a/utils.c b/utils.c
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--- a/utils.c
+++ /dev/null
@@ -1,711 +0,0 @@
-/*
- * utils.c: utilities
- *
- * Copyright (c) 2014, Přemysl Janouch <p.janouch@gmail.com>
- * All rights reserved.
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
- * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
- * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- *
- */
-
-#include <getopt.h>
-
-#if defined __GNUC__
-#define ATTRIBUTE_PRINTF(x, y) __attribute__ ((format (printf, x, y)))
-#else // ! __GNUC__
-#define ATTRIBUTE_PRINTF(x, y)
-#endif // ! __GNUC__
-
-#if defined __GNUC__ && __GNUC__ >= 4
-#define ATTRIBUTE_SENTINEL __attribute__ ((sentinel))
-#else // ! __GNUC__ || __GNUC__ < 4
-#define ATTRIBUTE_SENTINEL
-#endif // ! __GNUC__ || __GNUC__ < 4
-
-#define N_ELEMENTS(a) (sizeof (a) / sizeof ((a)[0]))
-
-#define BLOCK_START do {
-#define BLOCK_END } while (0)
-
-// --- Safe memory management --------------------------------------------------
-
-// When a memory allocation fails and we need the memory, we're usually pretty
-// much fucked. Use the non-prefixed versions when there's a legitimate
-// worry that an unrealistic amount of memory may be requested for allocation.
-
-static void *
-xmalloc (size_t n)
-{
- void *p = malloc (n);
- if (!p)
- {
- perror ("malloc");
- exit (EXIT_FAILURE);
- }
- return p;
-}
-
-static void *
-xcalloc (size_t n, size_t m)
-{
- void *p = calloc (n, m);
- if (!p && n && m)
- {
- perror ("calloc");
- exit (EXIT_FAILURE);
- }
- return p;
-}
-
-static void *
-xrealloc (void *o, size_t n)
-{
- void *p = realloc (o, n);
- if (!p && n)
- {
- perror ("realloc");
- exit (EXIT_FAILURE);
- }
- return p;
-}
-
-// --- Double-linked list helpers ----------------------------------------------
-
-#define LIST_HEADER(type) \
- type *next; \
- type *prev;
-
-#define LIST_PREPEND(head, link) \
- BLOCK_START \
- (link)->prev = NULL; \
- (link)->next = (head); \
- if ((link)->next) \
- (link)->next->prev = (link); \
- (head) = (link); \
- BLOCK_END
-
-#define LIST_UNLINK(head, link) \
- BLOCK_START \
- if ((link)->prev) \
- (link)->prev->next = (link)->next; \
- else \
- (head) = (link)->next; \
- if ((link)->next) \
- (link)->next->prev = (link)->prev; \
- BLOCK_END
-
-#define LIST_APPEND_WITH_TAIL(head, tail, link) \
- BLOCK_START \
- (link)->prev = (tail); \
- (link)->next = NULL; \
- if ((link)->prev) \
- (link)->prev->next = (link); \
- else \
- (head) = (link); \
- (tail) = (link); \
- BLOCK_END
-
-#define LIST_UNLINK_WITH_TAIL(head, tail, link) \
- BLOCK_START \
- if ((tail) == (link)) \
- (tail) = (link)->prev; \
- LIST_UNLINK ((head), (link)); \
- BLOCK_END
-
-// --- Dynamically allocated strings -------------------------------------------
-
-// Basically a string builder to abstract away manual memory management.
-
-struct str
-{
- char *str; ///< String data, null terminated
- size_t alloc; ///< How many bytes are allocated
- size_t len; ///< How long the string actually is
-};
-
-/// We don't care about allocations that are way too large for the content, as
-/// long as the allocation is below the given threshold. (Trivial heuristics.)
-#define STR_SHRINK_THRESHOLD (1 << 20)
-
-static void
-str_init (struct str *self)
-{
- self->alloc = 16;
- self->len = 0;
- self->str = strcpy (xmalloc (self->alloc), "");
-}
-
-static void
-str_free (struct str *self)
-{
- free (self->str);
- self->str = NULL;
- self->alloc = 0;
- self->len = 0;
-}
-
-static char *
-str_steal (struct str *self)
-{
- char *str = self->str;
- self->str = NULL;
- str_free (self);
- return str;
-}
-
-static void
-str_ensure_space (struct str *self, size_t n)
-{
- // We allocate at least one more byte for the terminating null character
- size_t new_alloc = self->alloc;
- while (new_alloc <= self->len + n)
- new_alloc <<= 1;
- if (new_alloc != self->alloc)
- self->str = xrealloc (self->str, (self->alloc = new_alloc));
-}
-
-static void
-str_append_data (struct str *self, const void *data, size_t n)
-{
- str_ensure_space (self, n);
- memcpy (self->str + self->len, data, n);
- self->len += n;
- self->str[self->len] = '\0';
-}
-
-static void
-str_append_c (struct str *self, char c)
-{
- str_append_data (self, &c, 1);
-}
-
-static void
-str_append (struct str *self, const char *s)
-{
- str_append_data (self, s, strlen (s));
-}
-
-static int
-str_append_vprintf (struct str *self, const char *fmt, va_list va)
-{
- va_list ap;
- int size;
-
- va_copy (ap, va);
- size = vsnprintf (NULL, 0, fmt, ap);
- va_end (ap);
-
- if (size < 0)
- return -1;
-
- va_copy (ap, va);
- str_ensure_space (self, size);
- size = vsnprintf (self->str + self->len, self->alloc - self->len, fmt, ap);
- va_end (ap);
-
- if (size > 0)
- self->len += size;
-
- return size;
-}
-
-static int
-str_append_printf (struct str *self, const char *fmt, ...)
- ATTRIBUTE_PRINTF (2, 3);
-
-static int
-str_append_printf (struct str *self, const char *fmt, ...)
-{
- va_list ap;
-
- va_start (ap, fmt);
- int size = str_append_vprintf (self, fmt, ap);
- va_end (ap);
- return size;
-}
-
-static void
-str_remove_slice (struct str *self, size_t start, size_t length)
-{
- size_t end = start + length;
- if (end > self->len)
- end = self->len;
- memmove (self->str + start, self->str + end, self->len - end);
- self->str[self->len -= length] = '\0';
-
- // Shrink the string if the allocation becomes way too large
- if (self->alloc >= STR_SHRINK_THRESHOLD && self->len < (self->alloc >> 2))
- self->str = xrealloc (self->str, self->alloc >>= 2);
-}
-
-// --- Utilities ---------------------------------------------------------------
-
-static bool
-set_blocking (int fd, bool blocking)
-{
- int flags = fcntl (fd, F_GETFL);
-
- bool prev = !(flags & O_NONBLOCK);
- if (blocking)
- flags &= ~O_NONBLOCK;
- else
- flags |= O_NONBLOCK;
-
- (void) fcntl (fd, F_SETFL, flags);
- return prev;
-}
-
-static void
-xclose (int fd)
-{
- while (close (fd) == -1)
- if (errno != EINTR)
- break;
-}
-
-static char *xstrdup_printf (const char *, ...) ATTRIBUTE_PRINTF (1, 2);
-
-static char *
-xstrdup_printf (const char *format, ...)
-{
- va_list ap;
- struct str tmp;
- str_init (&tmp);
- va_start (ap, format);
- str_append_vprintf (&tmp, format, ap);
- va_end (ap);
- return str_steal (&tmp);
-}
-
-static char *
-format_host_port_pair (const char *host, const char *port)
-{
- // IPv6 addresses mess with the "colon notation"; let's go with RFC 2732
- if (strchr (host, ':'))
- return xstrdup_printf ("[%s]:%s", host, port);
- return xstrdup_printf ("%s:%s", host, port);
-}
-
-static bool
-xstrtoul (unsigned long *out, const char *s, int base)
-{
- char *end;
- errno = 0;
- *out = strtoul (s, &end, base);
- return errno == 0 && !*end && end != s;
-}
-
-// --- libuv-style write adaptor -----------------------------------------------
-
-// Makes it possible to use iovec to write multiple data chunks at once.
-
-typedef struct write_req write_req_t;
-struct write_req
-{
- LIST_HEADER (write_req_t)
- struct iovec data; ///< Data to be written
-};
-
-typedef struct write_queue write_queue_t;
-struct write_queue
-{
- write_req_t *head; ///< The head of the queue
- write_req_t *tail; ///< The tail of the queue
- size_t head_offset; ///< Offset into the head
- size_t len;
-};
-
-static void
-write_queue_init (struct write_queue *self)
-{
- self->head = self->tail = NULL;
- self->head_offset = 0;
- self->len = 0;
-}
-
-static void
-write_queue_free (struct write_queue *self)
-{
- for (write_req_t *iter = self->head, *next; iter; iter = next)
- {
- next = iter->next;
- free (iter->data.iov_base);
- free (iter);
- }
-}
-
-static void
-write_queue_add (struct write_queue *self, write_req_t *req)
-{
- LIST_APPEND_WITH_TAIL (self->head, self->tail, req);
- self->len++;
-}
-
-static void
-write_queue_processed (struct write_queue *self, size_t len)
-{
- while (self->head
- && self->head_offset + len >= self->head->data.iov_len)
- {
- write_req_t *head = self->head;
- len -= (head->data.iov_len - self->head_offset);
- self->head_offset = 0;
-
- LIST_UNLINK_WITH_TAIL (self->head, self->tail, head);
- self->len--;
- free (head->data.iov_base);
- free (head);
- }
- self->head_offset += len;
-}
-
-static bool
-write_queue_is_empty (struct write_queue *self)
-{
- return self->head == NULL;
-}
-
-// --- Message reader ----------------------------------------------------------
-
-struct msg_reader
-{
- struct str buf; ///< Input buffer
- uint64_t offset; ///< Current offset in the buffer
-};
-
-static void
-msg_reader_init (struct msg_reader *self)
-{
- str_init (&self->buf);
- self->offset = 0;
-}
-
-static void
-msg_reader_free (struct msg_reader *self)
-{
- str_free (&self->buf);
-}
-
-static void
-msg_reader_compact (struct msg_reader *self)
-{
- str_remove_slice (&self->buf, 0, self->offset);
- self->offset = 0;
-}
-
-static void
-msg_reader_feed (struct msg_reader *self, const void *data, size_t len)
-{
- // TODO: have some mechanism to prevent flooding
- msg_reader_compact (self);
- str_append_data (&self->buf, data, len);
-}
-
-static void *
-msg_reader_get (struct msg_reader *self, size_t *len)
-{
- // Try to read in the length of the message
- if (self->offset + sizeof (uint64_t) > self->buf.len)
- return NULL;
-
- uint8_t *x = (uint8_t *) self->buf.str + self->offset;
- uint64_t msg_len
- = (uint64_t) x[0] << 56 | (uint64_t) x[1] << 48
- | (uint64_t) x[2] << 40 | (uint64_t) x[3] << 32
- | (uint64_t) x[4] << 24 | (uint64_t) x[5] << 16
- | (uint64_t) x[6] << 8 | (uint64_t) x[7];
-
- if (msg_len < sizeof msg_len)
- {
- // The message is shorter than its header
- // TODO: have some mechanism to report errors
- return NULL;
- }
-
- if (self->offset + msg_len < self->offset)
- {
- // Trying to read an insane amount of data but whatever
- msg_reader_compact (self);
- return NULL;
- }
-
- // Check if we've got the full message in the buffer and return it
- if (self->offset + msg_len > self->buf.len)
- return NULL;
-
- // We have to subtract the header from the reported length
- void *data = self->buf.str + self->offset + sizeof msg_len;
- self->offset += msg_len;
- *len = msg_len - sizeof msg_len;
- return data;
-}
-
-// --- Message unpacker --------------------------------------------------------
-
-struct msg_unpacker
-{
- const char *data;
- size_t offset;
- size_t len;
-};
-
-static void
-msg_unpacker_init (struct msg_unpacker *self, const void *data, size_t len)
-{
- self->data = data;
- self->len = len;
- self->offset = 0;
-}
-
-static size_t
-msg_unpacker_get_available (struct msg_unpacker *self)
-{
- return self->len - self->offset;
-}
-
-#define UNPACKER_INT_BEGIN \
- if (self->len - self->offset < sizeof *value) \
- return false; \
- uint8_t *x = (uint8_t *) self->data + self->offset; \
- self->offset += sizeof *value;
-
-static bool
-msg_unpacker_u8 (struct msg_unpacker *self, uint8_t *value)
-{
- UNPACKER_INT_BEGIN
- *value = x[0];
- return true;
-}
-
-static bool
-msg_unpacker_i32 (struct msg_unpacker *self, int32_t *value)
-{
- UNPACKER_INT_BEGIN
- *value
- = (uint32_t) x[0] << 24 | (uint32_t) x[1] << 16
- | (uint32_t) x[2] << 8 | (uint32_t) x[3];
- return true;
-}
-
-static bool
-msg_unpacker_u64 (struct msg_unpacker *self, uint64_t *value)
-{
- UNPACKER_INT_BEGIN
- *value
- = (uint64_t) x[0] << 56 | (uint64_t) x[1] << 48
- | (uint64_t) x[2] << 40 | (uint64_t) x[3] << 32
- | (uint64_t) x[4] << 24 | (uint64_t) x[5] << 16
- | (uint64_t) x[6] << 8 | (uint64_t) x[7];
- return true;
-}
-
-#undef UNPACKER_INT_BEGIN
-
-// --- Message packer and writer -----------------------------------------------
-
-struct msg_writer
-{
- struct str buf; ///< Holds the message data
-};
-
-static void
-msg_writer_init (struct msg_writer *self)
-{
- str_init (&self->buf);
- // Placeholder for message length
- str_append_data (&self->buf, "\x00\x00\x00\x00" "\x00\x00\x00\x00", 8);
-}
-
-static void
-msg_writer_u8 (struct msg_writer *self, uint8_t x)
-{
- str_append_data (&self->buf, &x, 1);
-}
-
-static void
-msg_writer_i32 (struct msg_writer *self, int32_t x)
-{
- uint32_t u = x;
- uint8_t tmp[4] = { u >> 24, u >> 16, u >> 8, u };
- str_append_data (&self->buf, tmp, sizeof tmp);
-}
-
-static void
-msg_writer_u64 (struct msg_writer *self, uint64_t x)
-{
- uint8_t tmp[8] =
- { x >> 56, x >> 48, x >> 40, x >> 32, x >> 24, x >> 16, x >> 8, x };
- str_append_data (&self->buf, tmp, sizeof tmp);
-}
-
-static void *
-msg_writer_flush (struct msg_writer *self, size_t *len)
-{
- // Update the message length
- uint64_t x = self->buf.len;
- uint8_t tmp[8] =
- { x >> 56, x >> 48, x >> 40, x >> 32, x >> 24, x >> 16, x >> 8, x };
- memcpy (self->buf.str, tmp, sizeof tmp);
-
- *len = x;
- return str_steal (&self->buf);
-}
-
-// --- Option handler ----------------------------------------------------------
-
-// Simple wrapper for the getopt_long API to make it easier to use and maintain.
-
-#define OPT_USAGE_ALIGNMENT_COLUMN 30 ///< Alignment for option descriptions
-
-enum
-{
- OPT_OPTIONAL_ARG = (1 << 0), ///< The argument is optional
- OPT_LONG_ONLY = (1 << 1) ///< Ignore the short name in opt_string
-};
-
-// All options need to have both a short name, and a long name. The short name
-// is what is returned from opt_handler_get(). It is possible to define a value
-// completely out of the character range combined with the OPT_LONG_ONLY flag.
-//
-// When `arg_hint' is defined, the option is assumed to have an argument.
-
-struct opt
-{
- int short_name; ///< The single-letter name
- const char *long_name; ///< The long name
- const char *arg_hint; ///< Option argument hint
- int flags; ///< Option flags
- const char *description; ///< Option description
-};
-
-struct opt_handler
-{
- int argc; ///< The number of program arguments
- char **argv; ///< Program arguments
-
- const char *arg_hint; ///< Program arguments hint
- const char *description; ///< Description of the program
-
- const struct opt *opts; ///< The list of options
- size_t opts_len; ///< The length of the option array
-
- struct option *options; ///< The list of options for getopt
- char *opt_string; ///< The `optstring' for getopt
-};
-
-static void
-opt_handler_free (struct opt_handler *self)
-{
- free (self->options);
- free (self->opt_string);
-}
-
-static void
-opt_handler_init (struct opt_handler *self, int argc, char **argv,
- const struct opt *opts, const char *arg_hint, const char *description)
-{
- memset (self, 0, sizeof *self);
- self->argc = argc;
- self->argv = argv;
- self->arg_hint = arg_hint;
- self->description = description;
-
- size_t len = 0;
- for (const struct opt *iter = opts; iter->long_name; iter++)
- len++;
-
- self->opts = opts;
- self->opts_len = len;
- self->options = xcalloc (len + 1, sizeof *self->options);
-
- struct str opt_string;
- str_init (&opt_string);
-
- for (size_t i = 0; i < len; i++)
- {
- const struct opt *opt = opts + i;
- struct option *mapped = self->options + i;
-
- mapped->name = opt->long_name;
- if (!opt->arg_hint)
- mapped->has_arg = no_argument;
- else if (opt->flags & OPT_OPTIONAL_ARG)
- mapped->has_arg = optional_argument;
- else
- mapped->has_arg = required_argument;
- mapped->val = opt->short_name;
-
- if (opt->flags & OPT_LONG_ONLY)
- continue;
-
- str_append_c (&opt_string, opt->short_name);
- if (opt->arg_hint)
- {
- str_append_c (&opt_string, ':');
- if (opt->flags & OPT_OPTIONAL_ARG)
- str_append_c (&opt_string, ':');
- }
- }
-
- self->opt_string = str_steal (&opt_string);
-}
-
-static void
-opt_handler_usage (struct opt_handler *self, FILE *stream)
-{
- struct str usage;
- str_init (&usage);
-
- str_append_printf (&usage, "Usage: %s [OPTION]... %s\n",
- self->argv[0], self->arg_hint ? self->arg_hint : "");
- str_append_printf (&usage, "%s\n\n", self->description);
-
- for (size_t i = 0; i < self->opts_len; i++)
- {
- struct str row;
- str_init (&row);
-
- const struct opt *opt = self->opts + i;
- if (!(opt->flags & OPT_LONG_ONLY))
- str_append_printf (&row, " -%c, ", opt->short_name);
- else
- str_append (&row, " ");
- str_append_printf (&row, "--%s", opt->long_name);
- if (opt->arg_hint)
- str_append_printf (&row, (opt->flags & OPT_OPTIONAL_ARG)
- ? " [%s]" : " %s", opt->arg_hint);
-
- // TODO: keep the indent if there are multiple lines
- if (row.len + 2 <= OPT_USAGE_ALIGNMENT_COLUMN)
- {
- str_append (&row, " ");
- str_append_printf (&usage, "%-*s%s\n",
- OPT_USAGE_ALIGNMENT_COLUMN, row.str, opt->description);
- }
- else
- str_append_printf (&usage, "%s\n%-*s%s\n", row.str,
- OPT_USAGE_ALIGNMENT_COLUMN, "", opt->description);
-
- str_free (&row);
- }
-
- fputs (usage.str, stream);
- str_free (&usage);
-}
-
-static int
-opt_handler_get (struct opt_handler *self)
-{
- return getopt_long (self->argc, self->argv,
- self->opt_string, self->options, NULL);
-}
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