diff options
Diffstat (limited to 'vcs-svn/svndiff.c')
-rw-r--r-- | vcs-svn/svndiff.c | 309 |
1 files changed, 0 insertions, 309 deletions
diff --git a/vcs-svn/svndiff.c b/vcs-svn/svndiff.c deleted file mode 100644 index 75c753162a..0000000000 --- a/vcs-svn/svndiff.c +++ /dev/null @@ -1,309 +0,0 @@ -/* - * 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_errno("cannot write delta postimage"); -} - -static int error_short_read(struct line_buffer *input) -{ - if (buffer_ferror(input)) - return error_errno("error reading delta"); - 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) -{ - assert(*delta_len >= 0); - strbuf_reset(buf); - if (len > (uintmax_t) *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) -{ - int rv = -1; - 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) { - rv = error("invalid delta: incorrect postimage length"); - goto error_out; - } - if (write_strbuf(&ctx.out, out)) - goto error_out; - rv = 0; -error_out: - window_release(&ctx); - return rv; -} - -int svndiff0_apply(struct line_buffer *delta, off_t delta_len, - struct sliding_view *preimage, FILE *postimage) -{ - assert(delta && preimage && postimage && delta_len >= 0); - - if (read_magic(delta, &delta_len)) - return -1; - while (delta_len) { /* For each window: */ - off_t pre_off = -1; - 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; -} |