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Diffstat (limited to '')
| -rw-r--r-- | wrapper.c | 680 |
1 files changed, 680 insertions, 0 deletions
diff --git a/wrapper.c b/wrapper.c new file mode 100644 index 0000000..bcda41e --- /dev/null +++ b/wrapper.c @@ -0,0 +1,680 @@ +/* + * Various trivial helper wrappers around standard functions + */ +#include "cache.h" +#include "config.h" + +static int memory_limit_check(size_t size, int gentle) +{ + static size_t limit = 0; + if (!limit) { + limit = git_env_ulong("GIT_ALLOC_LIMIT", 0); + if (!limit) + limit = SIZE_MAX; + } + if (size > limit) { + if (gentle) { + error("attempting to allocate %"PRIuMAX" over limit %"PRIuMAX, + (uintmax_t)size, (uintmax_t)limit); + return -1; + } else + die("attempting to allocate %"PRIuMAX" over limit %"PRIuMAX, + (uintmax_t)size, (uintmax_t)limit); + } + return 0; +} + +char *xstrdup(const char *str) +{ + char *ret = strdup(str); + if (!ret) + die("Out of memory, strdup failed"); + return ret; +} + +static void *do_xmalloc(size_t size, int gentle) +{ + void *ret; + + if (memory_limit_check(size, gentle)) + return NULL; + ret = malloc(size); + if (!ret && !size) + ret = malloc(1); + if (!ret) { + if (!gentle) + die("Out of memory, malloc failed (tried to allocate %lu bytes)", + (unsigned long)size); + else { + error("Out of memory, malloc failed (tried to allocate %lu bytes)", + (unsigned long)size); + return NULL; + } + } +#ifdef XMALLOC_POISON + memset(ret, 0xA5, size); +#endif + return ret; +} + +void *xmalloc(size_t size) +{ + return do_xmalloc(size, 0); +} + +static void *do_xmallocz(size_t size, int gentle) +{ + void *ret; + if (unsigned_add_overflows(size, 1)) { + if (gentle) { + error("Data too large to fit into virtual memory space."); + return NULL; + } else + die("Data too large to fit into virtual memory space."); + } + ret = do_xmalloc(size + 1, gentle); + if (ret) + ((char*)ret)[size] = 0; + return ret; +} + +void *xmallocz(size_t size) +{ + return do_xmallocz(size, 0); +} + +void *xmallocz_gently(size_t size) +{ + return do_xmallocz(size, 1); +} + +/* + * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of + * "data" to the allocated memory, zero terminates the allocated memory, + * and returns a pointer to the allocated memory. If the allocation fails, + * the program dies. + */ +void *xmemdupz(const void *data, size_t len) +{ + return memcpy(xmallocz(len), data, len); +} + +char *xstrndup(const char *str, size_t len) +{ + char *p = memchr(str, '\0', len); + return xmemdupz(str, p ? p - str : len); +} + +int xstrncmpz(const char *s, const char *t, size_t len) +{ + int res = strncmp(s, t, len); + if (res) + return res; + return s[len] == '\0' ? 0 : 1; +} + +void *xrealloc(void *ptr, size_t size) +{ + void *ret; + + if (!size) { + free(ptr); + return xmalloc(0); + } + + memory_limit_check(size, 0); + ret = realloc(ptr, size); + if (!ret) + die("Out of memory, realloc failed"); + return ret; +} + +void *xcalloc(size_t nmemb, size_t size) +{ + void *ret; + + if (unsigned_mult_overflows(nmemb, size)) + die("data too large to fit into virtual memory space"); + + memory_limit_check(size * nmemb, 0); + ret = calloc(nmemb, size); + if (!ret && (!nmemb || !size)) + ret = calloc(1, 1); + if (!ret) + die("Out of memory, calloc failed"); + return ret; +} + +/* + * Limit size of IO chunks, because huge chunks only cause pain. OS X + * 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in + * the absence of bugs, large chunks can result in bad latencies when + * you decide to kill the process. + * + * We pick 8 MiB as our default, but if the platform defines SSIZE_MAX + * that is smaller than that, clip it to SSIZE_MAX, as a call to + * read(2) or write(2) larger than that is allowed to fail. As the last + * resort, we allow a port to pass via CFLAGS e.g. "-DMAX_IO_SIZE=value" + * to override this, if the definition of SSIZE_MAX given by the platform + * is broken. + */ +#ifndef MAX_IO_SIZE +# define MAX_IO_SIZE_DEFAULT (8*1024*1024) +# if defined(SSIZE_MAX) && (SSIZE_MAX < MAX_IO_SIZE_DEFAULT) +# define MAX_IO_SIZE SSIZE_MAX +# else +# define MAX_IO_SIZE MAX_IO_SIZE_DEFAULT +# endif +#endif + +/** + * xopen() is the same as open(), but it die()s if the open() fails. + */ +int xopen(const char *path, int oflag, ...) +{ + mode_t mode = 0; + va_list ap; + + /* + * va_arg() will have undefined behavior if the specified type is not + * compatible with the argument type. Since integers are promoted to + * ints, we fetch the next argument as an int, and then cast it to a + * mode_t to avoid undefined behavior. + */ + va_start(ap, oflag); + if (oflag & O_CREAT) + mode = va_arg(ap, int); + va_end(ap); + + for (;;) { + int fd = open(path, oflag, mode); + if (fd >= 0) + return fd; + if (errno == EINTR) + continue; + + if ((oflag & O_RDWR) == O_RDWR) + die_errno(_("could not open '%s' for reading and writing"), path); + else if ((oflag & O_WRONLY) == O_WRONLY) + die_errno(_("could not open '%s' for writing"), path); + else + die_errno(_("could not open '%s' for reading"), path); + } +} + +static int handle_nonblock(int fd, short poll_events, int err) +{ + struct pollfd pfd; + + if (err != EAGAIN && err != EWOULDBLOCK) + return 0; + + pfd.fd = fd; + pfd.events = poll_events; + + /* + * no need to check for errors, here; + * a subsequent read/write will detect unrecoverable errors + */ + poll(&pfd, 1, -1); + return 1; +} + +/* + * xread() is the same a read(), but it automatically restarts read() + * operations with a recoverable error (EAGAIN and EINTR). xread() + * DOES NOT GUARANTEE that "len" bytes is read even if the data is available. + */ +ssize_t xread(int fd, void *buf, size_t len) +{ + ssize_t nr; + if (len > MAX_IO_SIZE) + len = MAX_IO_SIZE; + while (1) { + nr = read(fd, buf, len); + if (nr < 0) { + if (errno == EINTR) + continue; + if (handle_nonblock(fd, POLLIN, errno)) + continue; + } + return nr; + } +} + +/* + * xwrite() is the same a write(), but it automatically restarts write() + * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT + * GUARANTEE that "len" bytes is written even if the operation is successful. + */ +ssize_t xwrite(int fd, const void *buf, size_t len) +{ + ssize_t nr; + if (len > MAX_IO_SIZE) + len = MAX_IO_SIZE; + while (1) { + nr = write(fd, buf, len); + if (nr < 0) { + if (errno == EINTR) + continue; + if (handle_nonblock(fd, POLLOUT, errno)) + continue; + } + + return nr; + } +} + +/* + * xpread() is the same as pread(), but it automatically restarts pread() + * operations with a recoverable error (EAGAIN and EINTR). xpread() DOES + * NOT GUARANTEE that "len" bytes is read even if the data is available. + */ +ssize_t xpread(int fd, void *buf, size_t len, off_t offset) +{ + ssize_t nr; + if (len > MAX_IO_SIZE) + len = MAX_IO_SIZE; + while (1) { + nr = pread(fd, buf, len, offset); + if ((nr < 0) && (errno == EAGAIN || errno == EINTR)) + continue; + return nr; + } +} + +ssize_t read_in_full(int fd, void *buf, size_t count) +{ + char *p = buf; + ssize_t total = 0; + + while (count > 0) { + ssize_t loaded = xread(fd, p, count); + if (loaded < 0) + return -1; + if (loaded == 0) + return total; + count -= loaded; + p += loaded; + total += loaded; + } + + return total; +} + +ssize_t write_in_full(int fd, const void *buf, size_t count) +{ + const char *p = buf; + ssize_t total = 0; + + while (count > 0) { + ssize_t written = xwrite(fd, p, count); + if (written < 0) + return -1; + if (!written) { + errno = ENOSPC; + return -1; + } + count -= written; + p += written; + total += written; + } + + return total; +} + +ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset) +{ + char *p = buf; + ssize_t total = 0; + + while (count > 0) { + ssize_t loaded = xpread(fd, p, count, offset); + if (loaded < 0) + return -1; + if (loaded == 0) + return total; + count -= loaded; + p += loaded; + total += loaded; + offset += loaded; + } + + return total; +} + +int xdup(int fd) +{ + int ret = dup(fd); + if (ret < 0) + die_errno("dup failed"); + return ret; +} + +/** + * xfopen() is the same as fopen(), but it die()s if the fopen() fails. + */ +FILE *xfopen(const char *path, const char *mode) +{ + for (;;) { + FILE *fp = fopen(path, mode); + if (fp) + return fp; + if (errno == EINTR) + continue; + + if (*mode && mode[1] == '+') + die_errno(_("could not open '%s' for reading and writing"), path); + else if (*mode == 'w' || *mode == 'a') + die_errno(_("could not open '%s' for writing"), path); + else + die_errno(_("could not open '%s' for reading"), path); + } +} + +FILE *xfdopen(int fd, const char *mode) +{ + FILE *stream = fdopen(fd, mode); + if (stream == NULL) + die_errno("Out of memory? fdopen failed"); + return stream; +} + +FILE *fopen_for_writing(const char *path) +{ + FILE *ret = fopen(path, "w"); + + if (!ret && errno == EPERM) { + if (!unlink(path)) + ret = fopen(path, "w"); + else + errno = EPERM; + } + return ret; +} + +static void warn_on_inaccessible(const char *path) +{ + warning_errno(_("unable to access '%s'"), path); +} + +int warn_on_fopen_errors(const char *path) +{ + if (errno != ENOENT && errno != ENOTDIR) { + warn_on_inaccessible(path); + return -1; + } + + return 0; +} + +FILE *fopen_or_warn(const char *path, const char *mode) +{ + FILE *fp = fopen(path, mode); + + if (fp) + return fp; + + warn_on_fopen_errors(path); + return NULL; +} + +int xmkstemp(char *filename_template) +{ + int fd; + char origtemplate[PATH_MAX]; + strlcpy(origtemplate, filename_template, sizeof(origtemplate)); + + fd = mkstemp(filename_template); + if (fd < 0) { + int saved_errno = errno; + const char *nonrelative_template; + + if (strlen(filename_template) != strlen(origtemplate)) + filename_template = origtemplate; + + nonrelative_template = absolute_path(filename_template); + errno = saved_errno; + die_errno("Unable to create temporary file '%s'", + nonrelative_template); + } + return fd; +} + +/* Adapted from libiberty's mkstemp.c. */ + +#undef TMP_MAX +#define TMP_MAX 16384 + +int git_mkstemps_mode(char *pattern, int suffix_len, int mode) +{ + static const char letters[] = + "abcdefghijklmnopqrstuvwxyz" + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "0123456789"; + static const int num_letters = ARRAY_SIZE(letters) - 1; + static const char x_pattern[] = "XXXXXX"; + static const int num_x = ARRAY_SIZE(x_pattern) - 1; + uint64_t value; + struct timeval tv; + char *filename_template; + size_t len; + int fd, count; + + len = strlen(pattern); + + if (len < num_x + suffix_len) { + errno = EINVAL; + return -1; + } + + if (strncmp(&pattern[len - num_x - suffix_len], x_pattern, num_x)) { + errno = EINVAL; + return -1; + } + + /* + * Replace pattern's XXXXXX characters with randomness. + * Try TMP_MAX different filenames. + */ + gettimeofday(&tv, NULL); + value = ((uint64_t)tv.tv_usec << 16) ^ tv.tv_sec ^ getpid(); + filename_template = &pattern[len - num_x - suffix_len]; + for (count = 0; count < TMP_MAX; ++count) { + uint64_t v = value; + int i; + /* Fill in the random bits. */ + for (i = 0; i < num_x; i++) { + filename_template[i] = letters[v % num_letters]; + v /= num_letters; + } + + fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode); + if (fd >= 0) + return fd; + /* + * Fatal error (EPERM, ENOSPC etc). + * It doesn't make sense to loop. + */ + if (errno != EEXIST) + break; + /* + * This is a random value. It is only necessary that + * the next TMP_MAX values generated by adding 7777 to + * VALUE are different with (module 2^32). + */ + value += 7777; + } + /* We return the null string if we can't find a unique file name. */ + pattern[0] = '\0'; + return -1; +} + +int git_mkstemp_mode(char *pattern, int mode) +{ + /* mkstemp is just mkstemps with no suffix */ + return git_mkstemps_mode(pattern, 0, mode); +} + +int xmkstemp_mode(char *filename_template, int mode) +{ + int fd; + char origtemplate[PATH_MAX]; + strlcpy(origtemplate, filename_template, sizeof(origtemplate)); + + fd = git_mkstemp_mode(filename_template, mode); + if (fd < 0) { + int saved_errno = errno; + const char *nonrelative_template; + + if (!filename_template[0]) + filename_template = origtemplate; + + nonrelative_template = absolute_path(filename_template); + errno = saved_errno; + die_errno("Unable to create temporary file '%s'", + nonrelative_template); + } + return fd; +} + +static int warn_if_unremovable(const char *op, const char *file, int rc) +{ + int err; + if (!rc || errno == ENOENT) + return 0; + err = errno; + warning_errno("unable to %s '%s'", op, file); + errno = err; + return rc; +} + +int unlink_or_msg(const char *file, struct strbuf *err) +{ + int rc = unlink(file); + + assert(err); + + if (!rc || errno == ENOENT) + return 0; + + strbuf_addf(err, "unable to unlink '%s': %s", + file, strerror(errno)); + return -1; +} + +int unlink_or_warn(const char *file) +{ + return warn_if_unremovable("unlink", file, unlink(file)); +} + +int rmdir_or_warn(const char *file) +{ + return warn_if_unremovable("rmdir", file, rmdir(file)); +} + +int remove_or_warn(unsigned int mode, const char *file) +{ + return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file); +} + +static int access_error_is_ok(int err, unsigned flag) +{ + return (is_missing_file_error(err) || + ((flag & ACCESS_EACCES_OK) && err == EACCES)); +} + +int access_or_warn(const char *path, int mode, unsigned flag) +{ + int ret = access(path, mode); + if (ret && !access_error_is_ok(errno, flag)) + warn_on_inaccessible(path); + return ret; +} + +int access_or_die(const char *path, int mode, unsigned flag) +{ + int ret = access(path, mode); + if (ret && !access_error_is_ok(errno, flag)) + die_errno(_("unable to access '%s'"), path); + return ret; +} + +char *xgetcwd(void) +{ + struct strbuf sb = STRBUF_INIT; + if (strbuf_getcwd(&sb)) + die_errno(_("unable to get current working directory")); + return strbuf_detach(&sb, NULL); +} + +int xsnprintf(char *dst, size_t max, const char *fmt, ...) +{ + va_list ap; + int len; + + va_start(ap, fmt); + len = vsnprintf(dst, max, fmt, ap); + va_end(ap); + + if (len < 0) + BUG("your snprintf is broken"); + if (len >= max) + BUG("attempt to snprintf into too-small buffer"); + return len; +} + +void write_file_buf(const char *path, const char *buf, size_t len) +{ + int fd = xopen(path, O_WRONLY | O_CREAT | O_TRUNC, 0666); + if (write_in_full(fd, buf, len) < 0) + die_errno(_("could not write to '%s'"), path); + if (close(fd)) + die_errno(_("could not close '%s'"), path); +} + +void write_file(const char *path, const char *fmt, ...) +{ + va_list params; + struct strbuf sb = STRBUF_INIT; + + va_start(params, fmt); + strbuf_vaddf(&sb, fmt, params); + va_end(params); + + strbuf_complete_line(&sb); + + write_file_buf(path, sb.buf, sb.len); + strbuf_release(&sb); +} + +void sleep_millisec(int millisec) +{ + poll(NULL, 0, millisec); +} + +int xgethostname(char *buf, size_t len) +{ + /* + * If the full hostname doesn't fit in buf, POSIX does not + * specify whether the buffer will be null-terminated, so to + * be safe, do it ourselves. + */ + int ret = gethostname(buf, len); + if (!ret) + buf[len - 1] = 0; + return ret; +} + +int is_empty_or_missing_file(const char *filename) +{ + struct stat st; + + if (stat(filename, &st) < 0) { + if (errno == ENOENT) + return 1; + die_errno(_("could not stat %s"), filename); + } + + return !st.st_size; +} |