* Argh, another short-write problem. Added wrappers around

read()/write() to fix this once and for all.
This commit is contained in:
Eelco Dolstra 2003-07-20 21:11:43 +00:00
parent 667a6afb9d
commit 7984cfc7c1
9 changed files with 46 additions and 36 deletions

View file

@ -15,6 +15,9 @@ $hash || die "no package hash specified";
my $linkdir = "@localstatedir@/nix/links";
# Build the specified package, and all its dependencies.
system "nix -ih $hash";
if ($?) { die "`nix -ih' failed"; }
my $pkgdir = `nix -qph $hash`;
if ($?) { die "`nix -qph' failed"; }
chomp $pkgdir;

View file

@ -190,7 +190,7 @@ static string readString(RestoreSource & source)
{
unsigned int len = readInt(source);
char buf[len];
source((const unsigned char *) buf, len);
source((unsigned char *) buf, len);
readPadding(len, source);
return string(buf, len);
}

View file

@ -54,7 +54,7 @@ struct RestoreSource
pointed to by data. It should block if that much data is not
yet available, or throw an error if it is not going to be
available. */
virtual void operator () (const unsigned char * data, unsigned int len) = 0;
virtual void operator () (unsigned char * data, unsigned int len) = 0;
};
void restorePath(const string & path, RestoreSource & source);

View file

@ -215,12 +215,7 @@ struct StdoutSink : DumpSink
virtual void operator ()
(const unsigned char * data, unsigned int len)
{
while (len) {
ssize_t res = write(STDOUT_FILENO, (char *) data, len);
if (res == -1) throw SysError("writing to stdout");
len -= res;
data += res;
}
writeFull(STDOUT_FILENO, data, len);
}
};
@ -247,15 +242,9 @@ static void opDump(Strings opFlags, Strings opArgs)
/* A source that read restore intput to stdin. */
struct StdinSource : RestoreSource
{
virtual void operator () (const unsigned char * data, unsigned int len)
virtual void operator () (unsigned char * data, unsigned int len)
{
while (len) {
ssize_t res = read(STDIN_FILENO, (char *) data, len);
if (res == -1) throw SysError("reading from stdin");
if (res == 0) throw Error("unexpected end-of-file on stdin");
len -= res;
data += res;
}
readFull(STDIN_FILENO, data, len);
}
};

View file

@ -55,12 +55,11 @@ void checkPath(const string & path,
int fd = open(path.c_str(), O_RDONLY);
if (fd == -1) throw SysError(format("opening file `%1%'") % path);
char * buf = new char[st.st_size];
unsigned char * buf = new unsigned char[st.st_size];
if (read(fd, buf, st.st_size) != st.st_size)
throw SysError(format("reading file %1%") % path);
readFull(fd, buf, st.st_size);
search(string(buf, st.st_size), ids, seen);
search(string((char *) buf, st.st_size), ids, seen);
delete buf; /* !!! autodelete */

View file

@ -15,8 +15,7 @@ struct CopySink : DumpSink
int fd;
virtual void operator () (const unsigned char * data, unsigned int len)
{
if (write(fd, (char *) data, len) != (ssize_t) len)
throw SysError("writing to child");
writeFull(fd, data, len);
}
};
@ -24,13 +23,9 @@ struct CopySink : DumpSink
struct CopySource : RestoreSource
{
int fd;
virtual void operator () (const unsigned char * data, unsigned int len)
virtual void operator () (unsigned char * data, unsigned int len)
{
ssize_t res = read(fd, (char *) data, len);
if (res == -1)
throw SysError("reading from parent");
if (res != (ssize_t) len)
throw Error("not enough data available on parent");
readFull(fd, data, len);
}
};

View file

@ -37,21 +37,16 @@ struct MySink : DumpSink
virtual void operator () (const unsigned char * data, unsigned int len)
{
/* Don't use cout, it's slow as hell! */
if (write(STDOUT_FILENO, (char *) data, len) != (ssize_t) len)
throw SysError("writing to stdout");
writeFull(STDOUT_FILENO, data, len);
}
};
struct MySource : RestoreSource
{
virtual void operator () (const unsigned char * data, unsigned int len)
virtual void operator () (unsigned char * data, unsigned int len)
{
ssize_t res = read(STDIN_FILENO, (char *) data, len);
if (res == -1)
throw SysError("reading from stdin");
if (res != (ssize_t) len)
throw Error("not enough data available on stdin");
readFull(STDIN_FILENO, data, len);
}
};

View file

@ -159,3 +159,26 @@ void debug(const format & f)
{
msg(format("debug: %1%") % f.str());
}
void readFull(int fd, unsigned char * buf, size_t count)
{
while (count) {
ssize_t res = read(fd, (char *) buf, count);
if (res == -1) throw SysError("reading from file");
if (res == 0) throw Error("unexpected end-of-file");
count -= res;
buf += res;
}
}
void writeFull(int fd, const unsigned char * buf, size_t count)
{
while (count) {
ssize_t res = write(fd, (char *) buf, count);
if (res == -1) throw SysError("writing to file");
count -= res;
buf += res;
}
}

View file

@ -85,4 +85,10 @@ void msg(const format & f);
void debug(const format & f);
/* Wrappers arount read()/write() that read/write exactly the
requested number of bytes. */
void readFull(int fd, unsigned char * buf, size_t count);
void writeFull(int fd, const unsigned char * buf, size_t count);
#endif /* !__UTIL_H */