"rebase -i": support special-purpose editor to edit insn sheet

diff --git a/csum-file.c b/csum-file.c
index ace64f165e4a01fb99892e9b89e7df791a7f4ca1..fc97d6e04528b5c5b55fc211a462f3cb828f3d49 100644 (file)
--- a/csum-file.c
+++ b/csum-file.c
@@ -11,9 +11,19 @@
 #include "progress.h"
 #include "csum-file.h"
 
-static void sha1flush(struct sha1file *f, unsigned int count)
+static void flush(struct sha1file *f, void *buf, unsigned int count)
 {
-       void *buf = f->buffer;
+       if (0 <= f->check_fd && count)  {
+               unsigned char check_buffer[8192];
+               ssize_t ret = read_in_full(f->check_fd, check_buffer, count);
+
+               if (ret < 0)
+                       die_errno("%s: sha1 file read error", f->name);
+               if (ret < count)
+                       die("%s: sha1 file truncated", f->name);
+               if (memcmp(buf, check_buffer, count))
+                       die("sha1 file '%s' validation error", f->name);
+       }
 
        for (;;) {
                int ret = xwrite(f->fd, buf, count);
@@ -28,55 +38,80 @@ static void sha1flush(struct sha1file *f, unsigned int count)
                }
                if (!ret)
                        die("sha1 file '%s' write error. Out of diskspace", f->name);
-               die("sha1 file '%s' write error (%s)", f->name, strerror(errno));
+               die_errno("sha1 file '%s' write error", f->name);
        }
 }
 
-int sha1close(struct sha1file *f, unsigned char *result, unsigned int flags)
+void sha1flush(struct sha1file *f)
 {
-       int fd;
        unsigned offset = f->offset;
 
        if (offset) {
-               SHA1_Update(&f->ctx, f->buffer, offset);
-               sha1flush(f, offset);
+               git_SHA1_Update(&f->ctx, f->buffer, offset);
+               flush(f, f->buffer, offset);
                f->offset = 0;
        }
+}
+
+int sha1close(struct sha1file *f, unsigned char *result, unsigned int flags)
+{
+       int fd;
+
+       sha1flush(f);
+       git_SHA1_Final(f->buffer, &f->ctx);
+       if (result)
+               hashcpy(result, f->buffer);
        if (flags & (CSUM_CLOSE | CSUM_FSYNC)) {
                /* write checksum and close fd */
-               SHA1_Final(f->buffer, &f->ctx);
-               if (result)
-                       hashcpy(result, f->buffer);
-               sha1flush(f, 20);
+               flush(f, f->buffer, 20);
                if (flags & CSUM_FSYNC)
                        fsync_or_die(f->fd, f->name);
                if (close(f->fd))
-                       die("%s: sha1 file error on close (%s)",
-                           f->name, strerror(errno));
+                       die_errno("%s: sha1 file error on close", f->name);
                fd = 0;
        } else
                fd = f->fd;
+       if (0 <= f->check_fd) {
+               char discard;
+               int cnt = read_in_full(f->check_fd, &discard, 1);
+               if (cnt < 0)
+                       die_errno("%s: error when reading the tail of sha1 file",
+                                 f->name);
+               if (cnt)
+                       die("%s: sha1 file has trailing garbage", f->name);
+               if (close(f->check_fd))
+                       die_errno("%s: sha1 file error on close", f->name);
+       }
        free(f);
        return fd;
 }
 
 int sha1write(struct sha1file *f, void *buf, unsigned int count)
 {
-       if (f->do_crc)
-               f->crc32 = crc32(f->crc32, buf, count);
        while (count) {
                unsigned offset = f->offset;
                unsigned left = sizeof(f->buffer) - offset;
                unsigned nr = count > left ? left : count;
+               void *data;
+
+               if (f->do_crc)
+                       f->crc32 = crc32(f->crc32, buf, nr);
+
+               if (nr == sizeof(f->buffer)) {
+                       /* process full buffer directly without copy */
+                       data = buf;
+               } else {
+                       memcpy(f->buffer + offset, buf, nr);
+                       data = f->buffer;
+               }
 
-               memcpy(f->buffer + offset, buf, nr);
                count -= nr;
                offset += nr;
                buf = (char *) buf + nr;
                left -= nr;
                if (!left) {
-                       SHA1_Update(&f->ctx, f->buffer, offset);
-                       sha1flush(f, offset);
+                       git_SHA1_Update(&f->ctx, data, offset);
+                       flush(f, data, offset);
                        offset = 0;
                }
                f->offset = offset;
@@ -89,22 +124,43 @@ struct sha1file *sha1fd(int fd, const char *name)
        return sha1fd_throughput(fd, name, NULL);
 }
 
+struct sha1file *sha1fd_check(const char *name)
+{
+       int sink, check;
+       struct sha1file *f;
+
+       sink = open("/dev/null", O_WRONLY);
+       if (sink < 0)
+               return NULL;
+       check = open(name, O_RDONLY);
+       if (check < 0) {
+               int saved_errno = errno;
+               close(sink);
+               errno = saved_errno;
+               return NULL;
+       }
+       f = sha1fd(sink, name);
+       f->check_fd = check;
+       return f;
+}
+
 struct sha1file *sha1fd_throughput(int fd, const char *name, struct progress *tp)
 {
        struct sha1file *f = xmalloc(sizeof(*f));
        f->fd = fd;
+       f->check_fd = -1;
        f->offset = 0;
        f->total = 0;
        f->tp = tp;
        f->name = name;
        f->do_crc = 0;
-       SHA1_Init(&f->ctx);
+       git_SHA1_Init(&f->ctx);
        return f;
 }
 
 void crc32_begin(struct sha1file *f)
 {
-       f->crc32 = crc32(0, Z_NULL, 0);
+       f->crc32 = crc32(0, NULL, 0);
        f->do_crc = 1;
 }