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#include <iostream>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <dirent.h>
#include <fcntl.h>
extern "C" {
#include "md5.h"
}
#include "hash.hh"
Hash::Hash()
{
memset(hash, 0, sizeof(hash));
}
bool Hash::operator == (Hash & h2)
{
for (unsigned int i = 0; i < hashSize; i++)
if (hash[i] != h2.hash[i]) return false;
return true;
}
bool Hash::operator != (Hash & h2)
{
return !(*this == h2);
}
Hash::operator string() const
{
ostringstream str;
for (unsigned int i = 0; i < hashSize; i++) {
str.fill('0');
str.width(2);
str << hex << (int) hash[i];
}
return str.str();
}
Hash parseHash(const string & s)
{
Hash hash;
if (s.length() != Hash::hashSize * 2)
throw BadRefError("invalid hash: " + s);
for (unsigned int i = 0; i < Hash::hashSize; i++) {
string s2(s, i * 2, 2);
if (!isxdigit(s2[0]) || !isxdigit(s2[1]))
throw BadRefError("invalid hash: " + s);
istringstream str(s2);
int n;
str >> hex >> n;
hash.hash[i] = n;
}
return hash;
}
bool isHash(const string & s)
{
if (s.length() != 32) return false;
for (int i = 0; i < 32; i++) {
char c = s[i];
if (!((c >= '0' && c <= '9') ||
(c >= 'a' && c <= 'f')))
return false;
}
return true;
}
Hash hashString(const string & s)
{
Hash hash;
md5_buffer(s.c_str(), s.length(), hash.hash);
return hash;
}
Hash hashFile(const string & fileName)
{
Hash hash;
FILE * file = fopen(fileName.c_str(), "rb");
if (!file)
throw SysError("file `" + fileName + "' does not exist");
int err = md5_stream(file, hash.hash);
fclose(file);
if (err) throw SysError("cannot hash file " + fileName);
return hash;
}
struct HashSink : DumpSink
{
struct md5_ctx ctx;
virtual void operator ()
(const unsigned char * data, unsigned int len)
{
md5_process_bytes(data, len, &ctx);
}
};
Hash hashPath(const string & path)
{
Hash hash;
HashSink sink;
md5_init_ctx(&sink.ctx);
dumpPath(path, sink);
md5_finish_ctx(&sink.ctx, hash.hash);
return hash;
}
static void pad(unsigned int len, DumpSink & sink)
{
if (len % 8) {
unsigned char zero[8];
memset(zero, 0, sizeof(zero));
sink(zero, 8 - (len % 8));
}
}
static void writeInt(unsigned int n, DumpSink & sink)
{
unsigned char buf[8];
memset(buf, 0, sizeof(buf));
buf[0] = n & 0xff;
buf[1] = (n >> 8) & 0xff;
buf[2] = (n >> 16) & 0xff;
buf[3] = (n >> 24) & 0xff;
sink(buf, sizeof(buf));
}
static void writeString(const string & s, DumpSink & sink)
{
unsigned int len = s.length();
writeInt(len, sink);
sink((const unsigned char *) s.c_str(), len);
pad(len, sink);
}
static void dumpEntries(const string & path, DumpSink & sink)
{
DIR * dir = opendir(path.c_str());
if (!dir) throw SysError("opening directory " + path);
Strings names;
struct dirent * dirent;
while (errno = 0, dirent = readdir(dir)) {
string name = dirent->d_name;
if (name == "." || name == "..") continue;
names.push_back(name);
}
if (errno) throw SysError("reading directory " + path);
sort(names.begin(), names.end());
for (Strings::iterator it = names.begin();
it != names.end(); it++)
{
writeString("entry", sink);
writeString("(", sink);
writeString("name", sink);
writeString(*it, sink);
writeString("file", sink);
dumpPath(path + "/" + *it, sink);
writeString(")", sink);
}
closedir(dir); /* !!! close on exception */
}
static void dumpContents(const string & path, unsigned int size,
DumpSink & sink)
{
writeString("contents", sink);
writeInt(size, sink);
int fd = open(path.c_str(), O_RDONLY);
if (!fd) throw SysError("opening file " + path);
unsigned char buf[65536];
unsigned int total = 0;
ssize_t n;
while ((n = read(fd, buf, sizeof(buf)))) {
if (n == -1) throw SysError("reading file " + path);
total += n;
sink(buf, n);
}
if (total != size)
throw SysError("file changed while reading it: " + path);
pad(size, sink);
close(fd); /* !!! close on exception */
}
void dumpPath(const string & path, DumpSink & sink)
{
struct stat st;
if (lstat(path.c_str(), &st))
throw SysError("getting attributes of path " + path);
writeString("(", sink);
if (S_ISREG(st.st_mode)) {
writeString("type", sink);
writeString("regular", sink);
dumpContents(path, st.st_size, sink);
}
else if (S_ISDIR(st.st_mode)) {
writeString("type", sink);
writeString("directory", sink);
dumpEntries(path, sink);
}
else if (S_ISLNK(st.st_mode)) {
writeString("type", sink);
writeString("symlink", sink);
char buf[st.st_size];
if (readlink(path.c_str(), buf, st.st_size) != st.st_size)
throw SysError("reading symbolic link " + path);
writeString("target", sink);
writeString(string(buf, st.st_size), sink);
}
else throw Error("unknown file type: " + path);
writeString(")", sink);
}
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