diff --git a/Makefile b/Makefile index 91e20d29c6..e954dffa9e 100644 --- a/Makefile +++ b/Makefile @@ -342,6 +342,11 @@ BUILTIN_OBJS = BUILT_INS = COMPAT_CFLAGS = COMPAT_OBJS = +XDIFF_H = +XDIFF_OBJS = +VCSSVN_H = +VCSSVN_OBJS = +VCSSVN_TEST_OBJS = EXTRA_CPPFLAGS = LIB_H = LIB_OBJS = @@ -1832,11 +1837,23 @@ GIT_OBJS := $(LIB_OBJS) $(BUILTIN_OBJS) $(PROGRAM_OBJS) $(TEST_OBJS) \ ifndef NO_CURL GIT_OBJS += http.o http-walker.o remote-curl.o endif -XDIFF_OBJS = xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \ - xdiff/xmerge.o xdiff/xpatience.o -VCSSVN_OBJS = vcs-svn/line_buffer.o vcs-svn/repo_tree.o \ - vcs-svn/fast_export.o vcs-svn/svndump.o -VCSSVN_TEST_OBJS = test-line-buffer.o + +XDIFF_OBJS += xdiff/xdiffi.o +XDIFF_OBJS += xdiff/xprepare.o +XDIFF_OBJS += xdiff/xutils.o +XDIFF_OBJS += xdiff/xemit.o +XDIFF_OBJS += xdiff/xmerge.o +XDIFF_OBJS += xdiff/xpatience.o + +VCSSVN_OBJS += vcs-svn/line_buffer.o +VCSSVN_OBJS += vcs-svn/sliding_window.o +VCSSVN_OBJS += vcs-svn/repo_tree.o +VCSSVN_OBJS += vcs-svn/fast_export.o +VCSSVN_OBJS += vcs-svn/svndiff.o +VCSSVN_OBJS += vcs-svn/svndump.o + +VCSSVN_TEST_OBJS += test-line-buffer.o + OBJECTS := $(GIT_OBJS) $(XDIFF_OBJS) $(VCSSVN_OBJS) dep_files := $(foreach f,$(OBJECTS),$(dir $f).depend/$(notdir $f).d) @@ -1955,15 +1972,25 @@ connect.o transport.o http-backend.o: url.h http-fetch.o http-walker.o remote-curl.o transport.o walker.o: walker.h http.o http-walker.o http-push.o http-fetch.o remote-curl.o: http.h url.h -xdiff-interface.o $(XDIFF_OBJS): \ - xdiff/xinclude.h xdiff/xmacros.h xdiff/xdiff.h xdiff/xtypes.h \ - xdiff/xutils.h xdiff/xprepare.h xdiff/xdiffi.h xdiff/xemit.h - -$(VCSSVN_OBJS) $(VCSSVN_TEST_OBJS): $(LIB_H) \ - vcs-svn/line_buffer.h vcs-svn/repo_tree.h vcs-svn/fast_export.h \ - vcs-svn/svndump.h - -test-svn-fe.o: vcs-svn/svndump.h +XDIFF_H += xdiff/xinclude.h +XDIFF_H += xdiff/xmacros.h +XDIFF_H += xdiff/xdiff.h +XDIFF_H += xdiff/xtypes.h +XDIFF_H += xdiff/xutils.h +XDIFF_H += xdiff/xprepare.h +XDIFF_H += xdiff/xdiffi.h +XDIFF_H += xdiff/xemit.h + +xdiff-interface.o $(XDIFF_OBJS): $(XDIFF_H) + +VCSSVN_H += vcs-svn/line_buffer.h +VCSSVN_H += vcs-svn/sliding_window.h +VCSSVN_H += vcs-svn/repo_tree.h +VCSSVN_H += vcs-svn/fast_export.h +VCSSVN_H += vcs-svn/svndiff.h +VCSSVN_H += vcs-svn/svndump.h + +$(VCSSVN_OBJS) $(VCSSVN_TEST_OBJS): $(LIB_H) $(VCSSVN_H) endif exec_cmd.s exec_cmd.o: EXTRA_CPPFLAGS = \ diff --git a/t/t9011-svn-da.sh b/t/t9011-svn-da.sh new file mode 100755 index 0000000000..b38d16f9db --- /dev/null +++ b/t/t9011-svn-da.sh @@ -0,0 +1,248 @@ +#!/bin/sh + +test_description='test parsing of svndiff0 files + +Using the "test-svn-fe -d" helper, check that svn-fe correctly +interprets deltas using various facilities (some from the spec, +some only learned from practice). +' +. ./test-lib.sh + +>empty +printf foo >preimage + +test_expect_success 'reject empty delta' ' + test_must_fail test-svn-fe -d preimage empty 0 +' + +test_expect_success 'delta can empty file' ' + printf "SVNQ" | q_to_nul >clear.delta && + test-svn-fe -d preimage clear.delta 4 >actual && + test_cmp empty actual +' + +test_expect_success 'reject svndiff2' ' + printf "SVN\002" >bad.filetype && + test_must_fail test-svn-fe -d preimage bad.filetype 4 +' + +test_expect_success 'one-window empty delta' ' + printf "SVNQ%s" "QQQQQ" | q_to_nul >clear.onewindow && + test-svn-fe -d preimage clear.onewindow 9 >actual && + test_cmp empty actual +' + +test_expect_success 'reject incomplete window header' ' + printf "SVNQ%s" "QQQQQ" | q_to_nul >clear.onewindow && + printf "SVNQ%s" "QQ" | q_to_nul >clear.partialwindow && + test_must_fail test-svn-fe -d preimage clear.onewindow 6 && + test_must_fail test-svn-fe -d preimage clear.partialwindow 6 +' + +test_expect_success 'reject declared delta longer than actual delta' ' + printf "SVNQ%s" "QQQQQ" | q_to_nul >clear.onewindow && + printf "SVNQ%s" "QQ" | q_to_nul >clear.partialwindow && + test_must_fail test-svn-fe -d preimage clear.onewindow 14 && + test_must_fail test-svn-fe -d preimage clear.partialwindow 9 +' + +test_expect_success 'two-window empty delta' ' + printf "SVNQ%s%s" "QQQQQ" "QQQQQ" | q_to_nul >clear.twowindow && + test-svn-fe -d preimage clear.twowindow 14 >actual && + test_must_fail test-svn-fe -d preimage clear.twowindow 13 && + test_cmp empty actual +' + +test_expect_success 'noisy zeroes' ' + printf "SVNQ%s" \ + "RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRQQQQQ" | + tr R "\200" | + q_to_nul >clear.noisy && + len=$(wc -c clear.badmagic && + test_must_fail test-svn-fe -d preimage clear.badmagic 5 +' + +test_expect_success 'reject truncated integer' ' + printf "SVNQ%s%s" "QQQQQ" "QQQQRRQ" | + tr R "\200" | + q_to_nul >clear.fullint && + printf "SVNQ%s%s" "QQQQQ" "QQQQRR" | + tr RT "\201" | + q_to_nul >clear.partialint && + test_must_fail test-svn-fe -d preimage clear.fullint 15 && + test-svn-fe -d preimage clear.fullint 16 && + test_must_fail test-svn-fe -d preimage clear.partialint 15 +' + +test_expect_success 'nonempty (but unused) preimage view' ' + printf "SVNQ%b" "Q\003QQQ" | q_to_nul >clear.readpreimage && + test-svn-fe -d preimage clear.readpreimage 9 >actual && + test_cmp empty actual +' + +test_expect_success 'preimage view: right endpoint cannot backtrack' ' + printf "SVNQ%b%b" "Q\003QQQ" "Q\002QQQ" | + q_to_nul >clear.backtrack && + test_must_fail test-svn-fe -d preimage clear.backtrack 14 +' + +test_expect_success 'preimage view: left endpoint can advance' ' + printf "SVNQ%b%b" "Q\003QQQ" "\001\002QQQ" | + q_to_nul >clear.preshrink && + printf "SVNQ%b%b" "Q\003QQQ" "\001\001QQQ" | + q_to_nul >clear.shrinkbacktrack && + test-svn-fe -d preimage clear.preshrink 14 >actual && + test_must_fail test-svn-fe -d preimage clear.shrinkbacktrack 14 && + test_cmp empty actual +' + +test_expect_success 'preimage view: offsets compared by value' ' + printf "SVNQ%b%b" "\001\001QQQ" "\0200Q\003QQQ" | + q_to_nul >clear.noisybacktrack && + printf "SVNQ%b%b" "\001\001QQQ" "\0200\001\002QQQ" | + q_to_nul >clear.noisyadvance && + test_must_fail test-svn-fe -d preimage clear.noisybacktrack 15 && + test-svn-fe -d preimage clear.noisyadvance 15 && + test_cmp empty actual +' + +test_expect_success 'preimage view: reject truncated preimage' ' + printf "SVNQ%b" "\010QQQQ" | q_to_nul >clear.lateemptyread && + printf "SVNQ%b" "\010\001QQQ" | q_to_nul >clear.latenonemptyread && + printf "SVNQ%b" "\001\010QQQ" | q_to_nul >clear.longread && + test_must_fail test-svn-fe -d preimage clear.lateemptyread 9 && + test_must_fail test-svn-fe -d preimage clear.latenonemptyread 9 && + test_must_fail test-svn-fe -d preimage clear.longread 9 +' + +test_expect_success 'forbid unconsumed inline data' ' + printf "SVNQ%b%s%b%s" "QQQQ\003" "bar" "QQQQ\001" "x" | + q_to_nul >inline.clear && + test_must_fail test-svn-fe -d preimage inline.clear 18 >actual +' + +test_expect_success 'reject truncated inline data' ' + printf "SVNQ%b%s" "QQQQ\003" "b" | q_to_nul >inline.trunc && + test_must_fail test-svn-fe -d preimage inline.trunc 10 +' + +test_expect_success 'reject truncated inline data (after instruction section)' ' + printf "SVNQ%b%b%s" "QQ\001\001\003" "\0201" "b" | q_to_nul >insn.trunc && + test_must_fail test-svn-fe -d preimage insn.trunc 11 +' + +test_expect_success 'copyfrom_data' ' + echo hi >expect && + printf "SVNQ%b%b%b" "QQ\003\001\003" "\0203" "hi\n" | q_to_nul >copydat && + test-svn-fe -d preimage copydat 13 >actual && + test_cmp expect actual +' + +test_expect_success 'multiple copyfrom_data' ' + echo hi >expect && + printf "SVNQ%b%b%b%b%b" "QQ\003\002\003" "\0201\0202" "hi\n" \ + "QQQ\002Q" "\0200Q" | q_to_nul >copy.multi && + len=$(wc -c actual && + test_cmp expect actual +' + +test_expect_success 'incomplete multiple insn' ' + printf "SVNQ%b%b%b" "QQ\003\002\003" "\0203\0200" "hi\n" | + q_to_nul >copy.partial && + len=$(wc -c copy.incomplete && + len=$(wc -c expect && + printf "SVNQ%b%b%s" "QQ\006\004\003" "\0203\0100\003Q" "foo" | + q_to_nul >copytarget.repeat && + len=$(wc -c actual && + test_cmp expect actual +' + +test_expect_success 'copyfrom target out of order' ' + printf foooof >expect && + printf "SVNQ%b%b%s" \ + "QQ\006\007\003" "\0203\0101\002\0101\001\0101Q" "foo" | + q_to_nul >copytarget.reverse && + len=$(wc -c actual && + test_cmp expect actual +' + +test_expect_success 'catch copyfrom future' ' + printf "SVNQ%b%b%s" "QQ\004\004\003" "\0202\0101\002\0201" "XYZ" | + q_to_nul >copytarget.infuture && + len=$(wc -c expect && + printf "SVNQ%b%b%s" "QQ\014\004\003" "\0202\0111Q\0201" "XYZ" | + q_to_nul >copytarget.sustain && + len=$(wc -c actual && + test_cmp expect actual +' + +test_expect_success 'catch copy that overflows' ' + printf "SVNQ%b%b%s" "QQ\003\003\001" "\0201\0177Q" X | + q_to_nul >copytarget.overflow && + len=$(wc -c expect && + printf "SVNQ%b%b" "Q\003\003\002Q" "\003Q" | q_to_nul >copysource.all && + test-svn-fe -d preimage copysource.all 11 >actual && + test_cmp expect actual +' + +test_expect_success 'copy backwards' ' + printf oof >expect && + printf "SVNQ%b%b" "Q\003\003\006Q" "\001\002\001\001\001Q" | + q_to_nul >copysource.rev && + test-svn-fe -d preimage copysource.rev 15 >actual && + test_cmp expect actual +' + +test_expect_success 'offsets are relative to window' ' + printf fo >expect && + printf "SVNQ%b%b%b%b" "Q\003\001\002Q" "\001Q" \ + "\002\001\001\002Q" "\001Q" | + q_to_nul >copysource.two && + test-svn-fe -d preimage copysource.two 18 >actual && + test_cmp expect actual +' + +test_expect_success 'example from notes/svndiff' ' + printf aaaaccccdddddddd >expect && + printf aaaabbbbcccc >source && + printf "SVNQ%b%b%s" "Q\014\020\007\001" \ + "\004Q\004\010\0201\0107\010" d | + q_to_nul >delta.example && + len=$(wc -c actual && + test_cmp expect actual +' + +test_done diff --git a/test-svn-fe.c b/test-svn-fe.c index b42ba789b1..66bd04022d 100644 --- a/test-svn-fe.c +++ b/test-svn-fe.c @@ -4,15 +4,41 @@ #include "git-compat-util.h" #include "vcs-svn/svndump.h" +#include "vcs-svn/svndiff.h" +#include "vcs-svn/sliding_window.h" +#include "vcs-svn/line_buffer.h" int main(int argc, char *argv[]) { - if (argc != 2) - usage("test-svn-fe "); - if (svndump_init(argv[1])) - return 1; - svndump_read(NULL); - svndump_deinit(); - svndump_reset(); - return 0; + static const char test_svnfe_usage[] = + "test-svn-fe ( | [-d] )"; + if (argc == 2) { + if (svndump_init(argv[1])) + return 1; + svndump_read(NULL); + svndump_deinit(); + svndump_reset(); + return 0; + } + if (argc == 5 && !strcmp(argv[1], "-d")) { + struct line_buffer preimage = LINE_BUFFER_INIT; + struct line_buffer delta = LINE_BUFFER_INIT; + struct sliding_view preimage_view = SLIDING_VIEW_INIT(&preimage); + if (buffer_init(&preimage, argv[2])) + die_errno("cannot open preimage"); + if (buffer_init(&delta, argv[3])) + die_errno("cannot open delta"); + if (svndiff0_apply(&delta, (off_t) strtoull(argv[4], NULL, 0), + &preimage_view, stdout)) + return 1; + if (buffer_deinit(&preimage)) + die_errno("cannot close preimage"); + if (buffer_deinit(&delta)) + die_errno("cannot close delta"); + buffer_reset(&preimage); + strbuf_release(&preimage_view.buf); + buffer_reset(&delta); + return 0; + } + usage(test_svnfe_usage); } diff --git a/vcs-svn/LICENSE b/vcs-svn/LICENSE index 533f585ebf..eb91858b82 100644 --- a/vcs-svn/LICENSE +++ b/vcs-svn/LICENSE @@ -1,6 +1,8 @@ Copyright (C) 2010 David Barr . All rights reserved. +Copyright (C) 2010 Jonathan Nieder . + Copyright (C) 2005 Stefan Hegny, hydrografix Consulting GmbH, Frankfurt/Main, Germany and others, see http://svn2cc.sarovar.org diff --git a/vcs-svn/line_buffer.c b/vcs-svn/line_buffer.c index c39038723e..01fcb842f1 100644 --- a/vcs-svn/line_buffer.c +++ b/vcs-svn/line_buffer.c @@ -91,10 +91,10 @@ char *buffer_read_line(struct line_buffer *buf) return buf->line_buffer; } -void buffer_read_binary(struct line_buffer *buf, - struct strbuf *sb, uint32_t size) +size_t buffer_read_binary(struct line_buffer *buf, + struct strbuf *sb, size_t size) { - strbuf_fread(sb, size, buf->infile); + return strbuf_fread(sb, size, buf->infile); } off_t buffer_copy_bytes(struct line_buffer *buf, off_t nbytes) diff --git a/vcs-svn/line_buffer.h b/vcs-svn/line_buffer.h index d0b22dda76..8901f214ba 100644 --- a/vcs-svn/line_buffer.h +++ b/vcs-svn/line_buffer.h @@ -23,7 +23,7 @@ long buffer_tmpfile_prepare_to_read(struct line_buffer *buf); int buffer_ferror(struct line_buffer *buf); char *buffer_read_line(struct line_buffer *buf); int buffer_read_char(struct line_buffer *buf); -void buffer_read_binary(struct line_buffer *buf, struct strbuf *sb, uint32_t len); +size_t buffer_read_binary(struct line_buffer *buf, struct strbuf *sb, size_t len); /* Returns number of bytes read (not necessarily written). */ off_t buffer_copy_bytes(struct line_buffer *buf, off_t len); off_t buffer_skip_bytes(struct line_buffer *buf, off_t len); diff --git a/vcs-svn/sliding_window.c b/vcs-svn/sliding_window.c new file mode 100644 index 0000000000..1b8d9875ed --- /dev/null +++ b/vcs-svn/sliding_window.c @@ -0,0 +1,77 @@ +/* + * Licensed under a two-clause BSD-style license. + * See LICENSE for details. + */ + +#include "git-compat-util.h" +#include "sliding_window.h" +#include "line_buffer.h" +#include "strbuf.h" + +static int input_error(struct line_buffer *file) +{ + if (!buffer_ferror(file)) + return error("delta preimage ends early"); + return error("cannot read delta preimage: %s", strerror(errno)); +} + +static int skip_or_whine(struct line_buffer *file, off_t gap) +{ + if (buffer_skip_bytes(file, gap) != gap) + return input_error(file); + return 0; +} + +static int read_to_fill_or_whine(struct line_buffer *file, + struct strbuf *buf, size_t width) +{ + buffer_read_binary(file, buf, width - buf->len); + if (buf->len != width) + return input_error(file); + return 0; +} + +static int check_overflow(off_t a, size_t b) +{ + if (b > maximum_signed_value_of_type(off_t)) + return error("unrepresentable length in delta: " + "%"PRIuMAX" > OFF_MAX", (uintmax_t) b); + if (signed_add_overflows(a, (off_t) b)) + return error("unrepresentable offset in delta: " + "%"PRIuMAX" + %"PRIuMAX" > OFF_MAX", + (uintmax_t) a, (uintmax_t) b); + return 0; +} + +int move_window(struct sliding_view *view, off_t off, size_t width) +{ + off_t file_offset; + assert(view); + assert(view->width <= view->buf.len); + assert(!check_overflow(view->off, view->buf.len)); + + if (check_overflow(off, width)) + return -1; + if (off < view->off || off + width < view->off + view->width) + return error("invalid delta: window slides left"); + + file_offset = view->off + view->buf.len; + if (off < file_offset) { + /* Move the overlapping region into place. */ + strbuf_remove(&view->buf, 0, off - view->off); + } else { + /* Seek ahead to skip the gap. */ + if (skip_or_whine(view->file, off - file_offset)) + return -1; + strbuf_setlen(&view->buf, 0); + } + + if (view->buf.len > width) + ; /* Already read. */ + else if (read_to_fill_or_whine(view->file, &view->buf, width)) + return -1; + + view->off = off; + view->width = width; + return 0; +} diff --git a/vcs-svn/sliding_window.h b/vcs-svn/sliding_window.h new file mode 100644 index 0000000000..ed0bfdd65c --- /dev/null +++ b/vcs-svn/sliding_window.h @@ -0,0 +1,17 @@ +#ifndef SLIDING_WINDOW_H_ +#define SLIDING_WINDOW_H_ + +#include "strbuf.h" + +struct sliding_view { + struct line_buffer *file; + off_t off; + size_t width; + struct strbuf buf; +}; + +#define SLIDING_VIEW_INIT(input) { (input), 0, 0, STRBUF_INIT } + +extern int move_window(struct sliding_view *view, off_t off, size_t width); + +#endif diff --git a/vcs-svn/svndiff.c b/vcs-svn/svndiff.c new file mode 100644 index 0000000000..9ee41bbc90 --- /dev/null +++ b/vcs-svn/svndiff.c @@ -0,0 +1,308 @@ +/* + * Licensed under a two-clause BSD-style license. + * See LICENSE for details. + */ + +#include "git-compat-util.h" +#include "sliding_window.h" +#include "line_buffer.h" +#include "svndiff.h" + +/* + * svndiff0 applier + * + * See http://svn.apache.org/repos/asf/subversion/trunk/notes/svndiff. + * + * svndiff0 ::= 'SVN\0' window* + * window ::= int int int int int instructions inline_data; + * instructions ::= instruction*; + * instruction ::= view_selector int int + * | copyfrom_data int + * | packed_view_selector int + * | packed_copyfrom_data + * ; + * view_selector ::= copyfrom_source + * | copyfrom_target + * ; + * copyfrom_source ::= # binary 00 000000; + * copyfrom_target ::= # binary 01 000000; + * copyfrom_data ::= # binary 10 000000; + * packed_view_selector ::= # view_selector OR-ed with 6 bit value; + * packed_copyfrom_data ::= # copyfrom_data OR-ed with 6 bit value; + * int ::= highdigit* lowdigit; + * highdigit ::= # binary 1000 0000 OR-ed with 7 bit value; + * lowdigit ::= # 7 bit value; + */ + +#define INSN_MASK 0xc0 +#define INSN_COPYFROM_SOURCE 0x00 +#define INSN_COPYFROM_TARGET 0x40 +#define INSN_COPYFROM_DATA 0x80 +#define OPERAND_MASK 0x3f + +#define VLI_CONTINUE 0x80 +#define VLI_DIGIT_MASK 0x7f +#define VLI_BITS_PER_DIGIT 7 + +struct window { + struct sliding_view *in; + struct strbuf out; + struct strbuf instructions; + struct strbuf data; +}; + +#define WINDOW_INIT(w) { (w), STRBUF_INIT, STRBUF_INIT, STRBUF_INIT } + +static void window_release(struct window *ctx) +{ + strbuf_release(&ctx->out); + strbuf_release(&ctx->instructions); + strbuf_release(&ctx->data); +} + +static int write_strbuf(struct strbuf *sb, FILE *out) +{ + if (fwrite(sb->buf, 1, sb->len, out) == sb->len) /* Success. */ + return 0; + return error("cannot write delta postimage: %s", strerror(errno)); +} + +static int error_short_read(struct line_buffer *input) +{ + if (buffer_ferror(input)) + return error("error reading delta: %s", strerror(errno)); + return error("invalid delta: unexpected end of file"); +} + +static int read_chunk(struct line_buffer *delta, off_t *delta_len, + struct strbuf *buf, size_t len) +{ + strbuf_reset(buf); + if (len > *delta_len || + buffer_read_binary(delta, buf, len) != len) + return error_short_read(delta); + *delta_len -= buf->len; + return 0; +} + +static int read_magic(struct line_buffer *in, off_t *len) +{ + static const char magic[] = {'S', 'V', 'N', '\0'}; + struct strbuf sb = STRBUF_INIT; + + if (read_chunk(in, len, &sb, sizeof(magic))) { + strbuf_release(&sb); + return -1; + } + if (memcmp(sb.buf, magic, sizeof(magic))) { + strbuf_release(&sb); + return error("invalid delta: unrecognized file type"); + } + strbuf_release(&sb); + return 0; +} + +static int read_int(struct line_buffer *in, uintmax_t *result, off_t *len) +{ + uintmax_t rv = 0; + off_t sz; + for (sz = *len; sz; sz--) { + const int ch = buffer_read_char(in); + if (ch == EOF) + break; + + rv <<= VLI_BITS_PER_DIGIT; + rv += (ch & VLI_DIGIT_MASK); + if (ch & VLI_CONTINUE) + continue; + + *result = rv; + *len = sz - 1; + return 0; + } + return error_short_read(in); +} + +static int parse_int(const char **buf, size_t *result, const char *end) +{ + size_t rv = 0; + const char *pos; + for (pos = *buf; pos != end; pos++) { + unsigned char ch = *pos; + + rv <<= VLI_BITS_PER_DIGIT; + rv += (ch & VLI_DIGIT_MASK); + if (ch & VLI_CONTINUE) + continue; + + *result = rv; + *buf = pos + 1; + return 0; + } + return error("invalid delta: unexpected end of instructions section"); +} + +static int read_offset(struct line_buffer *in, off_t *result, off_t *len) +{ + uintmax_t val; + if (read_int(in, &val, len)) + return -1; + if (val > maximum_signed_value_of_type(off_t)) + return error("unrepresentable offset in delta: %"PRIuMAX"", val); + *result = val; + return 0; +} + +static int read_length(struct line_buffer *in, size_t *result, off_t *len) +{ + uintmax_t val; + if (read_int(in, &val, len)) + return -1; + if (val > SIZE_MAX) + return error("unrepresentable length in delta: %"PRIuMAX"", val); + *result = val; + return 0; +} + +static int copyfrom_source(struct window *ctx, const char **instructions, + size_t nbytes, const char *insns_end) +{ + size_t offset; + if (parse_int(instructions, &offset, insns_end)) + return -1; + if (unsigned_add_overflows(offset, nbytes) || + offset + nbytes > ctx->in->width) + return error("invalid delta: copies source data outside view"); + strbuf_add(&ctx->out, ctx->in->buf.buf + offset, nbytes); + return 0; +} + +static int copyfrom_target(struct window *ctx, const char **instructions, + size_t nbytes, const char *instructions_end) +{ + size_t offset; + if (parse_int(instructions, &offset, instructions_end)) + return -1; + if (offset >= ctx->out.len) + return error("invalid delta: copies from the future"); + for (; nbytes > 0; nbytes--) + strbuf_addch(&ctx->out, ctx->out.buf[offset++]); + return 0; +} + +static int copyfrom_data(struct window *ctx, size_t *data_pos, size_t nbytes) +{ + const size_t pos = *data_pos; + if (unsigned_add_overflows(pos, nbytes) || + pos + nbytes > ctx->data.len) + return error("invalid delta: copies unavailable inline data"); + strbuf_add(&ctx->out, ctx->data.buf + pos, nbytes); + *data_pos += nbytes; + return 0; +} + +static int parse_first_operand(const char **buf, size_t *out, const char *end) +{ + size_t result = (unsigned char) *(*buf)++ & OPERAND_MASK; + if (result) { /* immediate operand */ + *out = result; + return 0; + } + return parse_int(buf, out, end); +} + +static int execute_one_instruction(struct window *ctx, + const char **instructions, size_t *data_pos) +{ + unsigned int instruction; + const char *insns_end = ctx->instructions.buf + ctx->instructions.len; + size_t nbytes; + assert(ctx); + assert(instructions && *instructions); + assert(data_pos); + + instruction = (unsigned char) **instructions; + if (parse_first_operand(instructions, &nbytes, insns_end)) + return -1; + switch (instruction & INSN_MASK) { + case INSN_COPYFROM_SOURCE: + return copyfrom_source(ctx, instructions, nbytes, insns_end); + case INSN_COPYFROM_TARGET: + return copyfrom_target(ctx, instructions, nbytes, insns_end); + case INSN_COPYFROM_DATA: + return copyfrom_data(ctx, data_pos, nbytes); + default: + return error("invalid delta: unrecognized instruction"); + } +} + +static int apply_window_in_core(struct window *ctx) +{ + const char *instructions; + size_t data_pos = 0; + + /* + * Fill ctx->out.buf using data from the source, target, + * and inline data views. + */ + for (instructions = ctx->instructions.buf; + instructions != ctx->instructions.buf + ctx->instructions.len; + ) + if (execute_one_instruction(ctx, &instructions, &data_pos)) + return -1; + if (data_pos != ctx->data.len) + return error("invalid delta: does not copy all inline data"); + return 0; +} + +static int apply_one_window(struct line_buffer *delta, off_t *delta_len, + struct sliding_view *preimage, FILE *out) +{ + struct window ctx = WINDOW_INIT(preimage); + size_t out_len; + size_t instructions_len; + size_t data_len; + assert(delta_len); + + /* "source view" offset and length already handled; */ + if (read_length(delta, &out_len, delta_len) || + read_length(delta, &instructions_len, delta_len) || + read_length(delta, &data_len, delta_len) || + read_chunk(delta, delta_len, &ctx.instructions, instructions_len) || + read_chunk(delta, delta_len, &ctx.data, data_len)) + goto error_out; + strbuf_grow(&ctx.out, out_len); + if (apply_window_in_core(&ctx)) + goto error_out; + if (ctx.out.len != out_len) { + error("invalid delta: incorrect postimage length"); + goto error_out; + } + if (write_strbuf(&ctx.out, out)) + goto error_out; + window_release(&ctx); + return 0; +error_out: + window_release(&ctx); + return -1; +} + +int svndiff0_apply(struct line_buffer *delta, off_t delta_len, + struct sliding_view *preimage, FILE *postimage) +{ + assert(delta && preimage && postimage); + + if (read_magic(delta, &delta_len)) + return -1; + while (delta_len) { /* For each window: */ + off_t pre_off; + size_t pre_len; + + if (read_offset(delta, &pre_off, &delta_len) || + read_length(delta, &pre_len, &delta_len) || + move_window(preimage, pre_off, pre_len) || + apply_one_window(delta, &delta_len, preimage, postimage)) + return -1; + } + return 0; +} diff --git a/vcs-svn/svndiff.h b/vcs-svn/svndiff.h new file mode 100644 index 0000000000..74eb464bab --- /dev/null +++ b/vcs-svn/svndiff.h @@ -0,0 +1,10 @@ +#ifndef SVNDIFF_H_ +#define SVNDIFF_H_ + +struct line_buffer; +struct sliding_view; + +extern int svndiff0_apply(struct line_buffer *delta, off_t delta_len, + struct sliding_view *preimage, FILE *postimage); + +#endif